Will plumbing freeze? Toronto to Vancouver Mid-November

Harvard wrote:
It will freeze on the road in Nov, guaranteed. IMO

Indeed. In my years in Manitoba I don't recall one in which there was not freezing weather in October, let alone November.

Now, whether that means driving will be difficult is completely dependent on the specific forecast for the travel days.

If it were my trip, in a new RV, I'd winterize, and limit my usage to the toilet, and carry a couple of jugs of pinkstuff in addition to some water jugs.