Check with Guest Services at your hotel a couple days before you want to go to the Campfire and they'll usually have the movie schedule. Or call Ft. Wilderness directly. We did it earlier this month and it was big fun. The campfire started at 7, Chip and Dale were there for the sing-a-long, marshmallows were roasted, etc. I think the movie started between 7:45 and 8, but didn't have a watch so can't be specific. The movie that night was Pete's Dragon, but they rotate. It was a different movie two nights before that when we were originally planning to go, but the kids were pooped.
It was great fun, and free, can't beat that!
Enjoy!