Sam Ryan wrote:
If all that is true, then all the precautionary draining of water, including the water heater from the entire coach when stored in subfreezing conditions is wasted exercise and expense. As long as you have the time to wait for the water inside the coach to thaw, you're good to go. Good to know for storing the coach for extended periods below freezing.
Let us know how that works out for you Sam.

I think these people had a direct line to the guy upstairs. You, on the other hand, might want a spare water heater and pump on hand.
I've had three freeze ups - that I'm aware of. The P trap in our shower froze and broke one day while driving over one of the passes near our home. I was not expecting it to be that cold but watched as the BF's built-in thermostat hit 32 degrees a couple of times. That P trap hangs down in the open air and when we got home it was cracked and leaking. So be aware that one is very vulnerable. It's also not a critical failure and is very easily replaced.
Another time the hot water line froze in the corner behind the shower. After thawing it didn't leak. Pex seems pretty flexible that way. 'Had pex lines freeze in the house a couple of years ago and they also thawed and worked OK. I've since wired in a 200W AC trouble lamp on a thermostatic switch in that corner. I've written about that here:
http://www.bornfreervclub.org/bulletin_board/viewtopic.php?t=1200&postdays=0&postorder=asc&highlight=trouble+light+shower+thermostat&start=15
In the Spring after the 3rd year of winterizing by blowing out the lines I found the pump had suffered freeze damage. It had slow seeping leaks in the housing. I replaced it and have since used compressed air to blow out the pump when winterizing with no subsequent problems.