Personally, I would stay on the US side, even if only for the gas $ savings. I also totally despise driving in Toronto and would never do it with the MH or a TT.
If you're looking for a stopover along the way, there is a great campground in Massena, NY (Massena International Kampground) where we spend most of our camp time. Canadian $ at par - $34 all in (if you pay cash) for a FHU with cable. Can cross the border at Cornwall and scoot right around MTL on the previously mentioned toll highway, or continue further through the US and cross later.