Hey no way about Normandy; Am looking at doing that next year too!

. I was in the army for a short time and i liked them but some didn't! Theres lots of compitition between camping companies now for pre-made meals and they still are not that cheap in my opinion.
To keep costs down (and weight). I pre-made plenty of sandwiches... You need to think about the filling though! Ham gets warm,tomatoes will soak the bread etc.... I used Baguettes,they keep their shape and don't get squished! Lots of cereal bars/energy bars. Then you want stuff to cook,Pasta 'n' Sauce,supernoodles,cup-a-soups are all good for the weight. I have pre-buttered baguettes with any of those.

. Oh and if you do cupsoups use 2 sachets at a time,makes it thicker. Then stop at little shops along the way or the lay-by type places you get for pies,CAKE! and bacon & sausage barms!!!

. Have about 2 mars bars(or similar) a day too; Treat yourself to a pub meal every 2-3 days,it give you something to look forward to and keep your cals up.

. Since you know the route you will be taking google what supermarkets are in each larger town....I liked a cheap cereal bar from Asda so i knew where to stock up on that item later (and if your camping later you can get the curry boil in the bags for tea). Don't be shy in asking people could they top your water up for you,people are very forthcoming when they see all that kit and you look shattered!

. You can also do this at any pubs you may nip in....

.
Back to the 'RAT-PACKS'... I am looking at making my own using baco-bags and a sealer. Just another cheap option for you.

.