But it seems the Dowager Countess herself may not be so keen.
Speaking at the BFI & Radio Times Television Festival in London, Dame Maggie Smith refused to confirm the existence of any film plans, declaring: "I think it's best not to say."
However, when asked if she'd be up for a movie, she told the audience: "I just think it's squeezing it dry, do you know what I mean? I don't know what it could possibly be. It was so meandering, what would you - ?
"Anyway that's not my problem. That's the Lord's [Julian Fellowes'] problem."
However, if she were to return, Dame Maggie has an ideal storyline in mind for herself - and unfortunately it wouldn't involve much screen time for the Dowager Countess.
"I was firmly convinced it would start with the funeral," she said.
In Maggie's mind, Downton could echo Evelyn Waugh's Brideshead Revisited, where Lord Marchmain comes back to the family home only to die.
"I thought it would be a bit like that," she explained. "I could croak it. It would just start with the body. But I don't know. They talk about there being a film, but who knows? Who knows."
Is this the end of the story for the Dowager Countess? Who knows...