I shut off my water, and depressurize the system. I also shutdown and drain my water heater. I don't put anti-freeze in my traps though, but I probably will this year, at least in the bathtub and shower traps which are hard to repair if they do crack. I also have a relative check the house every week when we are not there. I set my furnace to a low setting, about 13 C, and shut down my HRV. I set up my sump pump to auto pump in case we get a fast thaw before we return, I set up the discharge line so that it will slowly drain back to the sump after the pump shuts off. This stops it from freezing solid should the weather go cold again.