Greetings,
Mr. cb. OK, now we're getting somewhere. Thanks. So...stovetop (apologies if some of this has been mentioned). Pastas, rice (either full cook-15min, minute rice-5 min or canned/packaged-
Rice Sides, Healthy & Quick Rice Side Dishes, Easy Rice Recipes - Knorr®, instant mashed potatoes-5 min. That's a few suggestions for your daily starch. These can all be stored at room temperature and just need water (mostly).
Protein: Canned meats and fish have been mentioned. If you like bacon and eggs for breakfast you can get canned bacon which will last forever unopened but once opened must be refrigerated. Eggs?
Liquid Eggs and Egg Whites | Egg Beaters | Egg Beaters Much easier to store in the fridge than an egg carton. Same size as a quart of milk.
Camping stores have a whole whack of freeze dried foods that you only have to add water and heat and again will store in any locker at room temperature.
Vegetables: Other than the longer lasting cabbage and potatoes you'll probably be limited to canned. Onions don't do too badly at room temp.
Condiments: Mayonnaise for the slaw and potato salad will have to be refrigerated after opening. Ketchup and mustard I
think is OK at room temp.
Additional: Vegetable oil (small container) for those fish you'll be catching and frying.
All of the above can readily be done on your cooktop stove or microwave and only a few items need be refrigerated. With the extra space in the fridge you can probably store some salad greens and veg. Cooler with ice for beverages and you may want to consider an extra cooler with dry ice as Mr. PM suggested. That way you can have pre-frozen steaks/chops etc. until the dry ice evaporates. I have no idea what the availability of dry ice will be along your route but you should be good for the first week at least.
Instant oatmeal for breakfasts although you'll need milk/cream (cream lasts a LOT longer than whole milk).
Many, many possibilities. You initially had me worried you were going to be living on Spam and PB&J sammiches for 3 weeks.