No need to worry about Montreal traffic anymore. Autoroute 30 bypasses the city on the south side of the river. This is a new multi-lane highway. There is a toll on the west end when you enter or leave the highway. Saves over an hour and during rush-hour saves even more time.
Lots of places to camp south of Montreal where you can unhook and drive into the city.
Not my favorite city in Canada but if you haven't been there you should give it a couple of days, after-all it is the home of the best hockey team in the world!!
Merry Christamas