We winterize after each time, but I have made some mods to be able to do the whole process in less than 10 minutes so it is really easy.
1) our pump and hot water heater is behind a panel under the sink so I made the panel "quick release" so I don't need to fuss with screws and a screwdriver each time.
2) our water heater has a bypass so that is already solved.
3) I bought a quick connect hose for the inlet of the pump. I still might buy the RV winterization kit that T's into the water line.
4) I bought the hand pump for pumping antifreeze in to the city water line.
Our winterization consists of bypassing and draining the water heater, squirting some antifreeze in the black tank flush system and city connection, and then connecting the hose to the suction side of the pump and pumping antifreeze to all the outlets. I pump a bit extra in each drain to cover the tanks too.
I don't bother with blowing the lines out and just use a bit more antifreeze. The whole process is really quick and is cheap insurance.
Usually we winterize as we are packing up the last day of the trip, but ironically, I never did it last weekend as we were supposed to be going back out this weekend and it is only September......
But, we have about a foot of snow now and it is going to be -4C (24F) tonight, so the trailer is getting a visit.
