That doesn't mean we can't carry food. As for the food already being expired, Twinkies DO expire. Everything does (except chocolate and honey), and with that, pickles last longer than twinkies. With 82 people, i understand that's going to be a lot of food, but the buffet is a bad idea. How many people would take more than needed in reality, leaving some people with nothing. As for food, I think it would be a good idea to assign certain people to rationing and handing out food to families. for an example: 1 can of food per person, if not two people. "Grab what you want" isn't going to work very well in a post appocolyptic setting.
Sorry if this sounds like a lecture, i get carried away with realism.