I can see where you are coming from. As a temporary measure, you can have a seamstress make curtains with Velcro sewn on and the other part of the Velcro attached to the ceiling or some other part.
www.truckfridge.com has some 12 volt refrigerators (true refrigerators, not thermo-electric coolers like Koolatrons which only drop temperatures 20 degrees.) They open from the top, the two larger portable fridges have freezers, and all have an option for a mounting bracket so it doesn't move around.
I'd also set up some provisions for sleeping as well, even if it is a sleeping bag and a camper's roll-up air mattress that is stashed somewhere. May never need it, but if/when you do, it will come in handy.