I'm a meal packer/room eater for all my trips, Disney or otherwise...to make travel affordable, we tend to eat out only 1-1.5/times per day of our trip, so bringing meals (and planning hotel meals) is a requirement.
I have a nice soft sided Eagles cooler bag, like this one...
https://www.bedbathandbeyond.com/st...c7AYIY86527xhYEH6P6KidIEHCJVcWihoCJU4QAvD_BwE
So, anything we don't want crushed or needs to stay cold goes in that bag, while my spouse will have a non-insulated back pack (usually to lug water/juice...aka the heavy, not squishing stuff)...
Usually I shop on site...but we are doing Niagara Falls and driving, so I'm bringing food. Breakfast is free every day at our hotel, so I'm planning light lunch (since it should be a big breakfast), drinks, and "dessert" for the room. I've already found some stupid cheap
Amazon single serve snack deals (chips/cookies) that I'm taking with me, plus a big jug of Goldfish. I also found Horizon chocolate milk and regular milk at my store for stupid-cheap a few weeks ago. Before we leave, I'll be adding squeezable yogurt (shelf-stable), squeezable apple sauce, 2 loaves of bread, Nutella, PB, honey, bananas, clementines (or pears - whatever is cheaper), shelf-stable salami and pepperoni (at Aldi's - for my spouse), shelf-stable ready to eat quinoa veg bowls (at Aldi's - these are for me - kids are doing the nut butter/fruit sandwiches), Capri sun roaring waters, bottled water, soda, paper plates, ziplocs, flushable wipes (good for every clean up), and a box of plastic silverware. We'll take drinks and lunch on the go as we're exploring and have dessert in the room before bed. Dinners are planned (and mostly paid for)...