Fellowes, 66, said he is very "pro-movie" and it will be a great idea, reported Digital Spy.
"I'm very pro-movie. I hope and think there's a very good shot. They have to be sure to have enough of the cast. They've all rushed off into other work in television, films, plays... So, I imagine it would be quite a job getting all the ducks in a row. But I'm not anti it at all," he said.