Well you should have left it in the foil wrapper

I've never, NEVER had any issues with film warming up in 120 foil or 35 plastic containers. If you put your film in zip locks that are closed properly, then moisture will not be an issue unless there was moister win the ziplock to begin with.
As for sheet film, my guess would be that if there's enough moisture to cause separation, then the film is most likely pooched anyways from ice crystals forming on the emulsion. but that'd be a wild guess unsupported by any factual evidence.