When traveling from Seattle to Boston, to use Highway #2 to Sault-Ste-Marie to Montreal then down 35 and 89 to Boston? Rather than travel the major highways in the US and pay the tolls? yes we know ...
I would say go for it if you have never driven across Canada before. We have, it is no longer on our bucket list. Just enjoy the scenery. Take your time, much less congestion. Meet nice folks along the way. Roads and routes will be ok. Enjoy.