Are there 2 F! showings that night? Typically rides close at park closing time, like if you're IN LINE at the time the park closes, you generally are allowed to ride. If F! starts at closing time as the only show, then you wouldn't really make it, obviously. I know people tend to leave right before the end of F! to catch Star Wars fireworks, and that seems to be the only way to do both on a one-F!-night...if there are 2 F!s then maybe see if your dining can be modified to the first showing?