I usually keep a bunch of stuff on hand that doesn't require refrigeration. I'll make 4 PB&J for a 4 day, makes a good breakfast if the hotel doesn't have it, or an easy and quick lunch. Also those premade tuna packets don't need to be kept cold. Beef jerky, almonds, sunflower nuts, granola bars, cliff bars, a couple of apples or pears. I usually just pack food to get me through the day, breakfast and lunch, and then I'll buy dinner on an overnight. It's a good way to save some money, avoid buying overpriced airport food, but not be completely anti social and feel like you're living on food from a wrapper for 4 days.

Also, unrelated somewhat, but those cold brew iced tea bags are great if you enjoy such things. Squeeze two in the top of a water bottle from the galley, hang the string out and close the lid, and by the time you're through 10,000 you've got a bottle of tea.