I drove part of the opposite itinerary a few weeks ago, Quebec City to Trois-Rivières, mostly on 132. It was a very pleasant drive through a pastoral landscape which I'd happily do again tomorrow if I could. The river comes in and out of view, sometimes foreshadowed by towers bearing navigation lights for river traffic. Some of the towns are picturesque. It was a very relaxing drive.

I was really struck by the St. Lawrence's size and level of traffic. Its flow is virtually identical to the Mississippi's, yet in most of the US I think it's practically unknown.

We took the 20 (following Google Maps' recommendation) from Montreal to Quebec City and I can't remember anything particularly interesting from that drive except the very charming young woman at the tourism information office . Don't miss the chance to visit L'Île d'Orléans while you're in the Quebec City area.