I'm in Oregon and the whole winterizing thing is always a tough one. For one I will sometimes use my RV over the winter so I hate to have it totally torn down. And it doesn't really get that cold that often here so I'm always on the fence about doing the full blown winterizing. When it dips below freezing I'll often just put a couple oil radiant heaters inside it to keep the temperature above 50.
I have a pretty slick setup with my RV right outside my kitchen window. One of the RV windows lines up perfectly so I just set a cheap-o dial type thermometer on the RV counter and I can see it from my house kitchen.
When I do the full winterize thing I use an air compressor to city water (on the RV) adapter and it works great. Just turn up the pressure to 40psi and open all the valves one at a time. Pour some anti-freeze down the drains and I'm all good. Oh yeah, have to deal with the water heater too.
As someone who dreams of spending MUCH more time in my RV as I age and work less, I'm hoping to completely forget how to winterize. My RV will be sitting in warmer places in the winter.