Windbreak not essential, I don't bother with ours.
Breakfast: we do like bacon rolls. Handy options are brioche rolls or instant porridge pots. Fruit.
Lunch: rolls and things which don't need refrigeration: tinned tuna, sandwich spread, an avocado. You can make toasties in a frying pan, you don't need hook up! Or better still, cheese (take a bag of ready grated) sandwiched between two tortilla wraps, or chapattis, and dry-fried in pan is good. Add Tuna, ham, whatever you like.
Dinner: we often BBQ. With one ring, pasta and a stir through sauce, and salad, take a frozen Tupperware of chilli, or bolognese, or stew, it will defrost during second day, heat up and have with swiftly heated tinned potatoes, or the pouch microwave rice, which can be heated in pan with a splash of water, or baguette, or whatever,
Take Baby Bel cheese, keeps well for snacks.
Check if site freezes cool blocks. Borrow a cooler box or bag. Pre freeze a pint of milk, your bacon, burgers or whatever for second or third day, and replace freezer blocks morning and evening. Don't leave cooler open or open more often than necessary.