Depends on the type of winterizing you do. I was an antifreeze guy until I bought our current camper where the water pump is buried beyond a reasonable point, now I just use air. This is my 4th winter using strictly air and almost zero problems.
If you want to use antifreeze, you'll want a bypass kit
for the hot water heater. You may also want a pump converter
to pump the antifreeze through the system. There's a few other ways to do that, but if you have good access, that is the easiest.