I'm currently working away from home, living in my 27'TT. Calgary Alberta area.
Current temperature is about minus 18C or 0F. Expected to see minus 24C / -11F by tomorrow morning.
It is a challenge and I'm going through a lot of propane, but so far so good. I keep the temperature a bit higher than I usually would to help keep pipes from freezing. I have had 3 temporary freezups behind the kitchen lower cabinets but was able to fix that up easily.
It can be done but a few precautions need to be taken.
Your windows will ice up on the inside.
I have a heat tape around my dump pipes and gate valves.
As mentioned, fill the fresh water and don't try the water hookup route.
Good luck!