User blog comment:Merlin Amanda/PROOF THAT CAMPAIGNING CAN WORK/@comment-5674726-20130712000216

The first crucial question is whether or not the cast are willing to return. If not, the show runners aren't going to recast for a movie or extra season.

The second crucial question is what they could do in terms of a plot. The finale ended things very conclusively. They have a little scope for setting a season in one of the gap periods but, even if they did, they'd have a very limited time frame to work with. A time travel storyline might work, with careful writing, and it would afford them the luxury of not needing all of the cast to return, since some roles could be recast with younger actors.