Will plumbing freeze? Toronto to Vancouver Mid-November

I've never traveled in below freezing conditions in my fiver, but if I had to, I would be sure the water pump was turned off, then I would relieve the pressure remaining in the lines. Upon reaching my destination, I wouldn't be too concerned about freezing water since the on board heating system should prevent any problem (underbelly was also heated). I wouldn't be boondocking in such a scenario, but using shore power.