OK, it's not generally the plan, but we've winterized and de-winterized twice so far this winter, and I'm getting it down to a pretty smooth routine. I'll just share this for the folk who wonder about the practicalities of winter camping.
I first winterized in October (it freezes early at 7400' in CO), and then we decided on a Thanksgiving trip from CO-WA. (previous posts). I don't use RV antifreeze in the potable water system, preferring to keep it chemical-free, I just use it in the drains and waste tanks. I do a good blow-out with air for the rest of the system.
We began this January trip from CO-AL on the 5th, picking up the trailer in Albuquerque from our dealer where we had left it for a couple of warranty repairs. It had been in the single digits for several nights in ABQ, and the dealers exterior spigots were all frozen, so I couldn't de-winterize the systems there. I turned on the furnace to thaw out the unit as we made the short tow to American RV Park (fine facility). Even there, we had to shift sites to find an unfrozen water spigot. With temp in the mid-20's and dropping, I tested the system with the city water connection, and we were leak-free. I then filled the potable tank. Switched on the water pump - nada. OK, I thought, maybe there's a bit of ice left in the pump impeller. I put our small electric heater in the plumbing space to blow on the pump, and sure enough it came to life after 15 minutes. No leaks - great. We were fully functional as the temp headed toward an overnight low of 9º.
The unit was perfectly warm and comfortable through our coldest night thus far (we've camped in the teens many times). I use the furnace rather than the heat pump as it warms the plumbing areas, and I don't leave the hoses connected overnight. I did have to use a tea kettle of hot water to thaw open the sewer cap and water spigot the next morning, but no real problems.
So, the Airstream has passed another test for our all-season adventures. She also survived our visit to the ABQ RV Show where the big motorhomes didn't tempt us in the least

. Onwards towards Alabama!