We do the antifreeze method. The water system in our camper is designed really well (I wish all of them were like this!) - it's all centralized into one compartment (pump, accumulator, filter, water heater & all the connections to allow for bypassing the HWH), and there is a separate inlet on the outside of the camper for pumping antifreeze through the system. It's great! We just finished doing it and it took us perhaps half an hour. :) Our winters haven't been that severe of late (minimum temperature probably about -15) and this method has served us well for quite a few years.