Stay away from MI roads!
(Granted not even close to your route but if you did go through Canada you may be tempted to come back to the US via MI--either in the UP, Port Huron, or Detroit--don't you'll be greeted by some of the worst roads in the nation! LOL)
I'd suggest a hovercraft retrofit to the RV then you wouldn't even feel the roads, and could take short cuts over the water.