Two things.
I like the RV type fridge just for the option of running off propane. Never have trouble leveling the rig for the fridge. If I'm comfortable, the fridge is comfortable.
Your friend might be a fantastic electrical engineer - but is he a solar power engineer. There are a lot of things to solar which regular EE never get into. Not a lot of EE are 12VDC experts. It is a very different animal than 120 and higher AC.
Because solar, battery banks and such is all about 12VDC - not the 120 part after the inverter. Because the description of the problem of the generator running sounds like a battery charging problem, not a solar problem or a fridge problem.
A household fridge should not be running enough to require the generator to run for six hours unless something is very wrong with the fridge.
What is the parasitic load on the rig?
That said - I'm not sure I would trust any RV dealer to actually know a lot about solar. Heck, a lot of RV salesmen and techs have never spent a night camping in an RV.
There are many people on this forum who are successful at running such appliances on solar for weeks each year.
