Lot of good information from the thread link posted. Propane
draws heat from surroundings to become a vapor from the liquid in the tank, the colder it is the slower that "boiling" will be. At cold temps and high demand a small propane
tank won't be able to keep up.
Used a propane heater in the garage. In really cold weather the 20 lb. tank could only run it for short periods before tank got frost on it and pressure dropped to the point the burner would die out, might even cause the pilot to go out. Larger 100 lb. tank would work, work lamp pointed at tank to help it stay warm would keep it going. Otherwise I had to run it for a short period, turn it back down for pressure to build up, then run it for a bit until tank got cold again and I had to shut down burner to allow gas pressure to build up to sufficient to run it some more.
What he factory does for winterizing may or may not be enough. Heat tape on plumbing, aux electric heat and skirting, making sure your propane can deal with the cold are all after market but known to work too. Having done a fair amount of winter camping without an RV I'm easily pleased, get it up to 50* inside and I would probably be fine.