i live in michigan an keep my boat in a unheated garage,all i do is lower the motor all the way down let the water run out put stabil in it,never had a problem an theres weeks in the winter it can stay in the teens here,if u live where it only goes down to say 30 an back up to the 50s during the day it will never freeze hard enough.its got to stay below freezing for 3-7 days before it starts to brake things.