And I didn't see it mentioned, but to state the obvious, when you bypass the water heater, drain the water heater so it doesn't freeze up and crack.
It's one of those things like when something electrical isn't working and you ask, "Is it plugged in?". But sometimes the obvious things are the easiest to forget.
Oh, and when I used to winterize, I just blew the airlines out, and poured a gallon into the drain traps and the grey/black tanks to protect the valves.
2011 Dodge Ram 1500 HEMI Quad Cab
2011 Jay Flight 26BH