The thing about Solar power for vehicles is that you’re limited to a very small total surface area so you can’t install much in the way of solar panels. I have two, 100watt panels on the roof of my minivan for a total of 200watts and 10Amps. I only get that under ideal Sun conditions where the Sun is nearly overhead and perfectly clear, unobstructed skies. In latitudes further North than Orlando, Florida, it can be a challenged to get full power from your panels in the winter and if you add in ANY cloud cover or atmospheric obstruction, all bets are off and your output can diminish a LOT. ANY shade from a tree, for example, and output can drop from 8Amps to 1Amp or less.
So in summary for solar IMO, it’s good in the summer and on clear days.
I have a 12v DC fridge but I also have a Igloo Iceless brand Peltier cooler that I’ve used for a few years. The Igloo cooler is a power hog and uses 6.2Amps ALL THE TIME it’s running. That said, it has never failed and has kept my foods at about 40F no matter what. But I have to use my generator every day to recharge the batteries. It’s rare that I have access to shore power.
Like Van_Dweller said, and I agree, the under $800 Chinese DC refrigerators are not very reliable. I don’t often see people bragging that they’ve been using one past about two years continuously so I’m thinking that’s about how long they last. The ONLY reason I went ahead and bought one is that I do AC work and and electronics repair so I can change the compressor and probably repair it when it fails. I plan to put a much better compressor in mine when it fails.
An alternative few think of is Dorm Refrigerators powered by an inverter. I have one. It’s from Walmart and was about $80 new. I think they’re about $100 now. Anyway, that is a good alternative because it is cheap, uses much less power than the Igloo cooler (but a little more than a DC fridge) , and is reliable compared to the cheap Chinese fridges. I have one running in my office 24/7. Just don’t put it in a vehicle that goes off-roading. Also, it depends on your vehicle because it can be a bit boxy and bulky.
The Yetti200x battery only has 187watt hours. That’s very little. I have a minimum of 2000watt hours of battery capacity (not counting the vehicles battery) at all times when I’m on the road and I find that I can go through that fairly quickly if not careful.
Depending on your plans and desires you will likely need more battery capacity than that. Maybe if you describe a bit more where you will spend most of your time in your vehicle and what kind of expectations you have it would help. I would also recommend you go on YouTube and find videos by Foresty Forest and watch them from the beginning. You’ll learn a lot about van dwelling just keep in mind he’s in Canada.
All that said, Solar power “Can” be useful depending on your location(s) and the season but under less than ideal conditions you will need a backup plan as Van_Dweller mentioned.
Remember…knowledge IS POWER!
Good luck!