After Grayson was diagnosed, I was putting his bowl in a Ziploc bag - went through A LOT of bags!!! Since then, I've picked up a 3-pack of (cereal size) Pyrex bowls w/ lids. For larger cans, it works well, or, if one cat doesn't finish, I just put a post-it w/ their name on the lid and pop in the fridge. Also DW safe. And because is the heavy-duty pyrex glass, when Moochie Pooch knocks his off the counter (which he does w/ ALL his empty food bowls to get my attention), they haven't shattered or even cracked! Makes my life easier. And I don't have to keep washing my dishes before I can eat! :lol:
As for the window of time on refrigerated food, I don't usually go beyond 2.5 days. In the can, with a lid, 1 day.