SIL has one of these for outdoor use with their popup.
https://www.amazon.com/Coleman-Quart...70_&dpSrc=srch
Had it for about 3 years now and works well enough to keep the ice runs down. Best part is that it works on 12v for when they are traveling to a fro.
If in your travels this summer you're going by or staying near a Coleman outlet I've seen them going for under $40.00 in their stores or tent sales.
Another option is a 110V dorm fridge like we have in our outdoor kitchens. Has to be one out there that will fit.
Agree the gas option is just too complex to achieve with all the proper venting required.