On 18 September 2016, Steve November has a problem. At 9:00pm that night, the slot arrives in ITV’s schedule that would normally be filled by the season premiere of Downton Abbey.

As Director of Drama for the ITV network, November has to find a replacement – Downton is ending, with the last ever episode to air this coming Christmas Day. And, given Downton’s blockbuster ratings performance, it’s going to be a fiendishly difficult act to follow.

"I genuinely think that the new Downton won’t be a country-house drama in the Edwardian period," says November, firmly. "The danger is that we say, ‘Edwardian period drama in that tone works – the new Downton will be something similar.’ The new Downton might be sci-fi, it might be something completely different."

Beyond that, November won’t be drawn on the detail of what he’s got in mind. Given the lead times for drama commissioning and production, though, one thing’s for sure: it’s a show that’s already either green-lit, or close to it.

"It could be one of three things, at least," says November. One obvious choice would be the recently announced Prime Suspect prequel, Tennison, which will see a young Jane battle police-force sexism in the 1970s. "Well, it could be, it could be crime," says November. "We’ve recently seen Black Work do great figures on a Sunday."

Black Work is a police series starring Sheridan Smith, who has also scored recent hits for ITV with Cilla and The Widower. Is Smith now the hottest female lead in British television?

"Wow, she might be – she does bring an audience, absolutely," says November. "So do Olivia Colman and Sarah Lancashire. We’re blessed at the moment in drama – there’s a vast range of really great male and female actors. But, yes, Sheridan’s got an undeniable everywoman quality."

"ITV keeps pushing out into different areas, trying new things. That range, taste and tone in the schedule is extraordinarily exciting."

And Black Work has not been November’s only new hit in 2015. Safe House (an average audience of 6.5 million) and Home Fires (6.2 million) both scored solid ratings, with Home Fires already recommissioned.

Indeed, ITV’s dramas are currently standing out as the ratings hits in its schedule. The network, overall, is performing much more poorly: so far this year, its share of viewing is just 14.7%, compared with 23.3% for its great rival, BBC One.

But November won’t be drawn into criticising ITV colleagues who are commissioning less popular shows in other genres. He points to entertainment’s Ninja Warrior UK as a breakout hit – and says he "thoroughly enjoyed" the computerised Spitting Image reboot, Newzoids. "That was the most satirical show in the run-up to the election – hard to do, right to do," he says. "ITV keeps pushing out into different areas, trying new things. That range, taste and tone in the schedule is extraordinarily exciting."

ITV’s drama slate has not been immune to ratings reverses: its soaps Emmerdale and Coronation Street have both seen dips recently.

"I wouldn’t call it an editorial problem, because I think it’s just a natural lifecycle of all the shows – it’s the same across EastEnders at the moment as well," argues November.

He adds that "there’s always a plan" for renewing the soaps, and points to the arrival of big-name cast signings Shayne Ward and Sarah Harding, but cautions: "We don’t want a soap ­revolution, because we’d kill off our audience."

November knows whereof he speaks. In the late 1990s, he worked on Sky 1’s soapy football drama, Dream Team – where he met his TV-writer wife, Hayley. Arriving at ITV 15 years ago, November was first a script editor at Emmerdale, before making a series of The Royal, and then being appointed Producer of Coronation Street.

"Working on soaps is just a lesson, constantly, day by day, in storytelling and production and everything about TV," he says. "So much, so rapidly. It’s fantastic." In 2008, he jumped from ITV’s production arm to ITV network drama commissioning, under Laura Mackie. He was responsible for returning series, including both the soaps and long-running stalwarts such as Midsomer Murders.

His portfolio back then included The Bill, which ran for more than 25 years as another week-in, week-out continuing series on ITV. Today, BBC One still scores solid audiences with Casualty and Holby City – and November says that ITV’s door isn’t closed to a third continuing franchise to go alongside Coronation Street and Emmerdale.

"We haven’t got plans for one at the moment, but we regularly look at our mix of drama and ask, ‘Is there something missing?’" he says.

So, if someone pitched you a year-round series? "We’d definitely consider it."

ITV drama is in expansive mood more generally. "We’ve got more drama hours in the schedule in 2016 and, hopefully, more again in 2017," says November. That uplift will be in the "tens of hours", marking a step-change in the volume of the network’s drama commissioning.

November’s recently enlarged team includes Controller of Drama Victoria Fea, Head of Drama Series Jane Hudson and commissioning editors Charlie Hampton and Sarah Conroy (who has joined the team permanently, staying on after she covered Hampton’s maternity leave).

As well as a burgeoning number of slots on the main ITV channel, November is now also commissioning for the Sky-only channel ITV Encore and, very soon, for ITV2 as well.

The last drama commissioned specifically for ITV2 was the unsuccessful Lacey Turner vehicle Switch, about young witches, which aired in 2012. Since then, ITV2 has become even more clearly focused on a 16- to 34-year-old audience.

November says he is not in a position to make any announcement, yet, but confirms that the new work is "not going to be teen. The protagonists need to feel a little more grown-up – in that in-between stage of life, where you’ve left home, you’re kind of an adult, but you haven’t actually set up your own home yet."

Initially, he will be commissioning around 10 hours a year for ITV2 – a similar scale to ITV Encore, whose exclusive carriage contract with Sky requires a certain amount of original drama commissioning. November’s latest ITV Encore commission is Houdini & Doyle, a 10-part British/Canadian co-production. The series offers a fictional take on the real-life friendship of Harry Houdini (played by American actor Michael Weston) and Sir Arthur Conan Doyle (Stephen Mangan), with the mismatched pair solving crimes each week. Despite the slightly forced international juxtapositions, November is adamant that this will be no "Europudding".

"Increasingly, I think broadcasters in the US, in France and the UK realise that, to attract the best talent, on-screen and off, people want that big shop window," he says. "Actually, co-pro brings you not a pudding, nowadays, but often a really enhanced show, with great talent."

November also believes that ITV drama has moved firmly on from what was perhaps the most unlikely race row of all time, when the producer of Midsomer Murders championed its all-white casting in 2011. November points to Marsha Thomason and Paterson Joseph, as two BAME lead characters out of three (alongside Christopher Eccleston) in Safe House.

But, on both BBC One and ITV1, dramas tend to feature occasional brown faces in a sea of white ones. Would November consider a series that featured predominantly BAME characters?

"We will continue to push for more and more diversity," he says. "Whether we want to say we’d go principally minority ethnic, I don’t know, because we’re trying to represent Britain as it is.

"If we went principally minority ethnic, we might feel like we’d oversteered and were playing to a more niche audience. We want to make shows that feel like they’re for absolutely everybody and therefore reflect the diversity in Britain.

"I think, therefore, for principally [BAME casts], we’d be saying, well, no. We just want a really great, authentic mix, to be honest."

That hunt for an authentic mix, which plays to the broadest audience, can sometimes lead to accusations that ITV drama lacks originality. "I think there is still – particularly within the inner-London hothouse of TV makers – a slightly skewed, out-of-date perception of what ITV is when it comes to risk-taking," says November. "There’s a kind of an inbred snobbery, which we have to fight quite hard."

November believes that audience tastes have moved on very quickly in the past couple of years. He points to Game of Thrones bringing fantasy into the mainstream, and also to The Missing, which included tricky things such as subtitled French. The Missing was developed at ITV, but ended up on BBC One, and November says that, in the end, ITV "watched it with a degree of envy". His advice to producers who are pitching is not to "second-guess or dumb down".

"Don’t self-edit. We will do bold," says November. "Mainstream is big, bold and broad – and we’re at the heart of it."