Check with the company. Just because they said there was no inverter does not mean you cannot put one in the truck.
Well I bought a 12 volt cooler to keep my milk and other things in, so far so good. just keeps it chilled, not cold, but better than nothing. I have a small 400 watt inverter that I bought yeas ago to power the laptop and c-pap.
If you plan on cooking complicated food like pasta, scrambled eggs and hash browns, you must have a solar powered truck. You know, the trucks that only run daylight to daylight and never see any nights. Cooking real food, cooking healthy foods is time consuming. You gotta manage your time well. Different foods have a different shelf life inside the truck. I know for a fact a dozen eggs has a shelf life of 1 week. That $7 whole roasted chicken from Walmart will be smelly after 11hrs. The only thing I store in my iceless cooler is sandwich ingredients, and microwaveable mixed vegetables (corn, carrots, green beans and peas). In the winter time, that’s when you want to have emergency food. A couple cans of Vienna sausages, corned beef, pork and beans, ect.. enough to last you for a week. For emergency situations like a blizzard. That north east blizzard that hit a couple of years ago. Yup I was stuck in a church parking lot, in Connecticut for 2 days. All I had was some bag of chips, 3 bags of donuts, 1 liter sprite and a couple water bottles.
It can be done especially if everything is chopped up. Everything can go in plastic freezer bags (which can be dumped in CA). FYI.......Mayo does not need to be refrigerated as long as it doesn’t get contaminated. Buy a small squeeze bottle. This goes for mustard too. I buy vinegar based dressing I don’t have to refrigerate plus their better for you than ranch.
I don’t know where you’re buying your eggs, but they should last longer than that. Now if they are boiled they MAY last a week.
The 12volts are good (used Kooltron for years) they cool better when ambient temperature is low. So running a/c will keep it cooler, but cost you mpg. I now run a 3500watt inverter, with a 120vac fridge from Walmart. Same size as OEM 12volt but only $120 not $1100 what the ‘stealership’ wants. Either way, saving money is the way to go, just don’t become a hermit, treat yourself to a restaurant meal from time to time. You’ll deserve it.