I use an electric chest freezer as our beverage cooler while boon docking. I start out with cold beverages and 20 lbs of ice and 20 lbs of water.. I can't let it run over night at the house, it would freeze everything solid. I let it run when the generator is on (mornings and afternoon) while boon docking. I have more issues with freezing than I do with warm beverages (once). With 60 lbs plus pounds of weight even on warm days (90f) I can go a day between turning it on. On cool days (60f)I can go 5 days and still have 33f water.
If you can withstand wide temperature swings, keep the fridge full, occupy extra space with ice, and limit door opening, it's doable. A manufacturer would not want to do this, but an owner, weighing his options and benefits might.
I think the freezer uses 200-300 watts,