I would first check to see if the stove top burners were working... Sometimes we have run into the PROPANE not making it into the trailer when it gets real cold outside. Perhaps the propane regulator freezing up???
We use a couple of these THERMO CUBES we got from AMAZON that turn on at 35 Degrees and turns off at 45 degrees. We can plug our 120VAC OIL FILLED HEATER into it. It also works great for plugging a 100WATT light bulb into it... Might help warming up the compartment abit where your propane tanks are located...

Roy Ken