Greetings
I understand dealing with cold. I live in Pennsylvania. The house I used to live in was old and the pipes froze often. We would keep the water running just barely. Also we had some kind of pipe heater things(sorry don't know name, 20 years ago). They looked like flat tape(1-1 1/2" wide) that wrapped around the pipes and then plugged it. They helped us alot, might help you also.
I can only send good thoughts for your tree.