Traveling in cold weather

Hello,
We have a 2010 BH--3670 and are currently workamping in SD and need to stay until mid DEC or so. We then will be traveling to AZ. I have a few questions about traveling(actual driving, not evenings as we will probably be in an RV park) when temps will be quite cold. Do I need to drain all water including the water heater? At what temp would I be ok to not drain the water? Any other advice while driving would be helpful.
Thanks,
Al

Not knowing the exact layout of your rig makes it tougher for me to advise you but here goes.
If your water system is somewhat insulated from direct exposure to the cold , by this I mean water lines tanks and such are buried in an underbelly especially a heated underbelly you could possibly avoid any freeze ups while traveling for periods.
Keep the hot water tank hot while parked and it will retain heat for travelling.
Now the real factor is how far below freezing it is and how long you plan to travel each time?

I would recommend you have a heat gun to try thaw things in the event of a freeze up.
The use of an open flame heat source becomes really sketchy and can lead to an event you do not want happening lol.
I was forced to thaw my dumping valves on one occasion with a plumbers propane torch during our close up and winterize weekend and it was not pleasant hehe.

Others may have more experience with your rig and have some real life experiences to add .

I have traveled in 10 degree weather and didn't drain anything. Left the furnace and water on and nothing frooze.

The water heater will not be a problem as it takes quite a while for the water in the tank to cool.

We've driven to and from the Colorado mountains numerous times in December, January and February without draining any water. We left Breckenridge at -2 (F) one time without any problem.

But generally we've traveled on days where the highs were at least above freezing.

Make sure your interior temp is up to at least 70 before leaving. The heat in the coach will help.

Maybe use foam pipe insulation on your fresh water drain and low point drains if you have them.

Thanks--appreciate the advice---