We use ours during the winter months frequently so winterizing is out of the question. I use a small electric heater plugged into a automatic thermostat plug-in switch; Not sure exactly but comes on at around 32 degrees and cuts off at around 40 degrees. I open doors and access panels to water heater and water tank to allow for air circulation. As cold as it has been the last couple of weeks I have also turned on the Gas heat and set the thermostat at the lowest setting  I think it was around 36 degrees, for added protection in case of losing electrical power.

I winterized mine when the real cold hits.  The for the next couple of months, I just don't put any water into the system. Camp outs are never as serious in the winter months as they are the other 9 months of the year. So I can survive with bottled water for any over nighters.

Now if I was to load up and haul down to Vegas or someplace warmer for a couple of days of riding, I fill the water and rewinterize when  I got back home. But for overnighters it not worth the trouble.