Do you really think couple of bear are going to touch you in mid game in your base? I'm pretty sure I won't go out to hunt them during mid game..I also think spoilage would be pretty lame, but I agree that there could be some value to having food-related challenges in the mid-to-late game.
Instead of food generically increasing heat for zombies, what about it creating a different sort of heat that attracts bears? So the more food items you have in a chunk, ESPECIALLY raw meat, the more often a bear comes wandering in to check it out. Just like the screamer mechanic.
The challenge goes from ‘don’t starve’ to ‘don’t get eaten!’ and instead of feeling like food is a non-issue after a certain point it becomes a different kind of issue, one of abundance = danger.
In fact if you had hundreds of meat and food items you could expect 2-3 bears to come sniffing around and more frequent dog pack spawns.
This way when you get to the point you’ve got tons of food and forges/cement mixers/chem stations working you have zombies AND animals frequently checking out your base.
But this wouldn’t prevent you from questing, exploring, etc. It would just mean there’s a good chance when you come home there will be a bear or two near your base.