Running refrigerator in cold trailer

+1 on the light bulb, or heat tape on the coils. My fridge got too cold during a winter storm in MT 5 years ago and the unit stopped cooling. I had heard if you turned the unit upside-down overnight it would remix the stuff in the coils it will restart. Was so sick of storing food in the snow drift so I pulled it out one day by myself (female, 5'7", 115 lbs) turned it over, and the next morning it fired right up. Been working great ever since. :) Learned from that to keep the back of the fridge warm when temps drop far below freezing. There was only one guy in that park whose fridge didn't freeze and his furnace was situated right under his refrigerator.