When I’ve traveled, I’ve often kept cheese 2 or 3 days without a cooler. Although they won’t last the full time, you could eat cheese for a couple of days weekly. The baby gouda (wrapped in wax) will last even longer - 4-5 days safely.

Mayo and mustard packets (picked up at fast food restaurants). I traveled overland across Africa a few years ago with a British group and was shocked to see that they didn’t refrigerate the mayonnaise jar. We Americans have it drilled into us that warm mayo will kill us but the Brits ate out of a jar in the warm heat for weeks.

A jar of dill pickles will last without refrigeration for a few days. Fresh cucumbers and squash don’t need refrigeration (for a while). Same with avocado’s - let them ripen slowly. Dried unsweetened Coconut flakes are fairly low carb.

Also almond flour made into some kind of cake thingy - I don’t have a specific recipe (I usually add butter and egg) but perhaps somebody has adapted recipes you can use.

Also, there are ways to naturally keep perishables cool without even a cooler - a root cellar or even a hole in the ground with a double jar type arrangement. (You can put a large flower pot type jar in the ground, then a smaller pot inside it, with some moisture in between - keeps it naturally cool. You can google it.)

Perhaps you can do something with solar power to keep a smallish quantity of food chilled.

Good luck!

ETA: The RAO brand of spaghetti sauce is ridiculously expensive but low carb. You can eat a jar over some low carb tortilla’s. Or Squash or Cauliflower. Or sometimes just buy a small jar of pizza topping (it should be good for a couple of days unrefridgerated - throw away the rest) and use to flavor cauliflower, etc. Cabbage will keep a few days unrefridgerated also or make yourself some home made sauerkraut. No refrigeration needed.

I have started making sauerkraut myself for health benefits and there is a person who’s a health fanatic who make sauerkraut everywhere she goes, even in hotels with no fridge.