Here is a link that has some posts about my own experience of camping (unexpectedly) in sub-freezing temperatures.
http://www.trailmanorowners.com/foru...ad.php?t=11319
A few things I learned:
1. Electric heaters in the TM are a big help. They can be set to maintain the temp above freezing level while you are away. They also keep the temps high enough at night to keep from having to use the TM heater. It heats very well, but it sounds like a hurricane is passing through your trailer.
2. If you keep the interior above freezing, the fresh water tank and toilet don't freeze. The grey water will unless you put some anti-freeze in it. Leave the cupboard doors open on the sink side to let heat in where the water is, and leave the bathroom door ajar.
3. You can let it get pretty cold at night in the coach if you have good warm covers or a good sleeping bag.
4. The water hose will definitely freeze. Don't use one of those exterior filters in low temperatures. They split when they freeze up. Do use the pressure regulator, they are metal and don't split. You just turn the interior water pump on in the morning until the hose thaws out.
5. Many people use flotation "noodles" on the bed ends to keep out drafts. We just carry some towels for that purpose. Whatever works. We never have felt drafts through the flaps.
Tom