couple of months in warm conditions is definitely going to show in the final image. whether it matters or not depends on the project and shooting style.
I would refrigerate the partially shot cartridge on its own as Mark suggested.
I personally process the shot material at intervals of about 3 - 4 months and never had any problems with it.
I keep the shot stock refrigerated and it is rarely in the camera for more than from 1 day to one week if shooting doc stuff and 1 hour to 1 day for other stuff.
I would not recommend 3 months in camera even with the 50D (I don't do that even with 35mm 5203) unless you are going to shoot at regular short intervals which makes refrigerating unpractical, for example one shot every day for 3 months.
Maybe would first store it in a plastic bag with silica gel pads for some time if it was partially shot in humid conditions and you are worrying about condensation/mold growth.
it is gelatin after all, microbes love it if given a chance
Edited by aapo lettinen, 16 July 2016 - 04:36 PM.