The Look What We Found pouches of things like stew, chilli etc are very good. Not esp cheap, but tasty and good quality, and often on sp offer in Sainsbury's, Wairose etc. They have long sell by dates so I buy them when on sp offer and save for the camping season.
YY to taking a frozen meal like spag bol, chilli or curry in the freezer box (You can leave out some of the freezer blocks to make room. as it will keep other stuff nice and cold) It will be fine for a about 48 hours.
We like to make up chicken noodle soup from a dried packet and slice smoked ready cooked sausage in at the end. Its a great lunch really tasty and it doesnt need to be kept cool (Even though though those type of sausage are normally in the fridge section...Mmmmmatersons dont actually need to be there if you read the packet.)
For a large group it can be worth firing up the bbq just to cook the meat, so something simple like pork chops (topped with some crumbly feta at the last minute) and served with a naice salad, crusty bread and a glass of wine can feel like a feast. It doesnt have to be a full on BBQ.
We like to peel the skin back on bananas slightly and put in slices of mars bar and put them on the fire BBQ- absolutely scrummy.
We tend to stick to cereals mostly for breakfast, unless its a sunday and then we have pancakes!
Tuna Pasta is always a winner and again no need for a fridge.
Lots of sandwiches/wraps at lunch time and as everyone says the obligatory chippy tea!