My mother’s fridge is only maintaining a temp of 6C (you want 4). While waiting for a new fridge she was concerned about this. I explained that for the first 15-20 years of her life, their was kept cold by putting in a cabinet with a block of ice in it. She calmed down a lot about it after that. :)

I dig what you’re getting at here man, however my advice is just get a little propane camp stove. Mine has improved my camping life so greatly I’m kicking myself for not buying one before. It’s not even expensive one and you can cook in no time flat anywhere. That being said Tuna and crackers is a classic, there is a lot more canned meat than tuna and you can get a lot of variety out of crackers.

It depends if you’re not trying to poop that whole time?

I mean I would just eat cold canned ravioli because that’s delicious and it would be a great excuse to eat cold canned ravioli, but you do you

If you’re in England look into the Duke of Edinburgh club. It’s an outdoors camping club for youth. You should be able to find a packing list and it will have food suggestions.

jerky, granola, lots of vegetables are fairly stable and can be eaten raw. Carrots, garden peas, green beans, lettuce (you can eat that in the first day or two before it wilts), apples,

Beans

No easy access to fire? Is that because fire is forbidden or because getting wood and/or a place to burn stuff isn’t available? If it’s the latter, a gas burner is your friend

You can easily make overnight oats with dry ingredients (oats, fruit, nuts/seeds, some syrup) and some water each evening and then have them for breakfast/lunch.

Ramen and soylent

That’s just long enough for things that aren’t shelf stable to start going bad, depending on local conditions. Bread can mold in a couple days though, in warm and humid places.

So, focus in on shelf-stable or preserved things, whether made in a modern method, (sterile packaging of some sort) or an old fashioned method, (drying, curing, smoking) or just naturally able to keep (nuts, seeds, chocolate, honey).

Someone posted their granola bar recipe, that looked pretty solid. I would certainly not bring a bunch of pasties or a calzone unless I was also bringing a cooler. Then I’d be bringing ingredients and tools and making them on-site just for fun, as I assume I’m now car camping, or at least camping fairly close to my vehicle. If backpacking in, then absolutely not. Ready-to-eat, shelf-stable stuff only, to cut weight and stay efficient. And a pasty or calzone would squish in the backpack and end up gross anyway.

Boiled eggs and boiled potatoes. They will surely last 3 days.

Tortillas

Cup noodles can be made with cold water too. But they will take about 30 mins instead of 2-3 minutes. Tried and tested. They still taste good. They are not very nutritious, though.

I would recommended making Energy Bars/Balls. You can find a lot of recipes online but here’s mine:

• Roasted almonds
• Roasted cashews
• Roasted pistachios
• Roasted hazelnuts
• Roasted walnuts
• Raisins
• Dates
• Dried Cranberries
• Peanut Butter (unsweetened) (mine contains coconut oil)
• Sesame seeds
• Muskmelon seeds
• Flax seeds
• Pumpkin seeds
• Dark Chocolate

1. Roast the nuts and grind almonds and walnuts to almost flour consistency, and grind the others coarsly.
2. Just put everything in a food processor and let it mix everything. You can also mix it with hand or spoon.
3. To make bars, just put the mixture in a baking dish or a tray and put as much pressure as you can on top of it with your hands or spoon to remove all the air pockets. Refrigerate it for 4 hours. Then cut it into bars.
4. To make balls, just lightly oil your hands and form a ball shape. Again, press them hard to remove the air pockets.

These can last over a week outside the refrigerator (considering the ambient temperature in your area does not rise above 30° C). And inside the refrigerator they can last for over a month.

You can add different types of seeds, nuts, sweeteners etc, depending on what you like, what your body needs and what’s available.

Hope this helps.

Lots of good answers here.

Another option would be taking MRE-s (meal ready to eat) it’s pre-packaged food designed for soldiers to eat while not having access to a kitchen. It usually has a solution to heat the food and plenty of calories for a full day.

You can order them on the Internet from military surplus or other places and there is a bunch of flavours to choose from. They also have a long shelf life, don’t need refrigeration, and fit in a small space.