At the recent Overland East Expo, we came across a unique portable freezer/refrigerator from Dometic that is capable of freezing ice cream solid, down to -7 degrees F (-22 C)!
Yet in seperate compartments in the same cooler, it will keep veggies and soft drinks from getting too cold. Dometic's Jeff Spencer gave us a demo and, yes, we ate the ice cream we grabbed from box – once it thawed enough not to break our teeth.
It's expensive ($608), but if you do a lot of camping and boondocking, it is worth it and, in combination with your RV's standard refrigerator, will really extend your camping. The one we liked the best is the 40 quart size, the. Here's a link to it on Amazon – http://amzn.to/2zkYMX2
Temperature can be set and monitored with an easy-to-use Wi-Fi App