If you plan for shelf-stable foods, you don't even need a cooler. A loaf of crusty bread, a summer sausage, a block of cheese, and some apples/grapes/carrots should all be fine at room temp for a few days. I just keep most of it in my room and cut/tear off a day's worth into a zip-lock bag each morning. That goes in the outside pocket of my tote along with some granola bars. Easy peasy.
I also brought a re-fillable water bottle & some vitamin-C powder things to mix into it, both to avoid buying pricay drinks and because 70k people = germs.
I did get food truck food truck sandwiches here and there just to avoid getting burned out on my rations, but that's OK.