Peter will probably chime in soon.
My trailer already had a dorm
fridge in it when I bought it. After looking at the idea of running it off the battery with an inverter and using solar cells or charging off the car or both, I decided to buy a large cooler instead. The
fridge is now storage for bread, chips and similar stuff. It can be done, but from what I've read it is a challenge to implement the right plan with the right equipment so it will actually work. One needs a good bunch of rather expensive parts, and skimping will result in disappointing performance.