Water tank is drained. lines are pretty much drained, hw heater is drained or not, if it isn't going to freeze why worry? Probably a good idea to put 5 to 10 gallons in water tank with a couple of ounces of bleach and run through the system when commissioning, flush that through until tank is MT then fill tank and flush a little to clear the bleach, then open the by-pass to the water heater and fill. I rather like doing the bleach thing in the tank rather than city water inlet just to make sure the on-board water is good for drinking, making coffee and brushing teeth. Ever take a shower and not get water in your mouth, eyes, ears or?? Yes, we drink from the spigot but we super clean the hose every now and again.