If you don't have any heat in the house, you should winterize. Ours can be done in 20 minutes with less than $5 worth of pink antifreeze.
With heat, no problem for the toilet (door open so bathroom is heated). Not a bad idea to put a jug of water or antifreeze as close to the pump as possible - water has a large heat capacity (10 times the same mass of metal) and will keep the area around it from freezing for a few hours.
The plastic water pipes are a little flexible so somewhat resistant to ice breaking. Our fresh water drain tap froze a few times but no harm was done.
I have a wireless thermometer I can use to watch the house temperature from inside the house; easy to keep an eye on it in the middle of the night and avoid going out if the temperature is above freezing.
I am surprised to hear it is so cool way down south. We've only gone a degree or two below freezing three nights here so far in northern Alberta.
