If you don't boondock then why not go 12V fridge? I have one and I wired it directly to the batteries with an inline fuse. No inverter needed. More storage than a typical absorption fridge. Cools down faster as well.
2x100 solar panels on the roof and it will keep the batteries charged when cooling down before a trip and while on route.
Most newer 12V fridges are plug n play with the OEM absorption fridges from Norcold and Dometic.
Option 2 would be 200w solar, 1000W inverter and a res fridge. Just make sure the res fridge meets the space requirements.
The biggest battery draw is in the initial cool down. Once cool the fridge doesn't draw down the battery as bad.
2 batteries would be the minimum for either fridge.
Not sure what your plan is for cooling the fridge and taking off on your trip.
If your only needing one night for cool down the just 2 batteries would work, and then on your travels the truck will help maintain the batteries till you get to your 120V hookup.
If you're looking at needing several days of cool down then you'll need to supplement the batteries with some solar.