How long do you go between shopping stops? How many are you cooking for?
With two people on a ten-week trip this past year, cooking/preparing all our own food except for maybe two meals per week on average, I had no trouble with running out of room in a two-door fridge. We did go grocery shopping once or maybe twice per week when it was convenient, and of course did not store excess stuff in the fridge or freezer that didn't require refrigeration--for instance, only a couple cans of soda rather than the whole twelve can case.
I've heard anecdotally that the larger RV absorption fridges tend to have a harder time keeping cold than the smaller ones--it seems the cooling units aren't always enlarged equally with the storage space. I don't know if that's actual fact or merely my impressions.
Residential fridges can be used when dry camping if one has sufficient battery bank capacity and some way of charging that. I'd think probably four batteries would be about the practical minimum, and some combination of a fair bit of solar power (and hopefully campsites and locations that make it useful), a generator and decent converter to run a couple/few hours a day, or a reasonable charging circuit from the vehicle alternator if one is moving along most days. Others probably have more precise suggestions in this regard. But, if set up properly, it can be a practical way to go.
