A good  route would be to bypass the midwest all together (both Canada 
and the US) and take a larger loop through the South and then up through 
Vermont. Maine and New Hampshire (the Vermont border is only 1.5 hrs from 
either Montreal or Ottawa) both worth visiting..by the way...

We have driven back and forth across NA about five times once in a 
Karmann Ghia convert- scary - and in thev van, and believe me the places not 
too miss are Wyoming, Colorado, Arizona, S Dakota, BC, NE Ontario, and 
parts of CA.  Thats my two cents - DC