I like enjoy this type of touring: Flat, small grades and able to chew up a lot of miles. I also enjoy the desert and great plains. Easy to plan for reaching the next town because there is no steep mountain pass in between that will suck all energy out of you.
Highway 17 along Lake Superior is a roller coaster, with pretty steep grades (10+%). Highway 11 which veers farther north through Hearst and Kapuskasing is a flatter alternative with less traffic. The Canadian Shield geology is mostly extremely tough granite which makes road building expensive and difficult, so they tended to do minimal grading on the old highways. If you come across road construction where they're flattening or straightening there's a lot of dynamite involved. So many rivers and lakes though, if you have a filter you'll never be short of water.
But on the roads in Ontario and Quebec I have no idea what the real situation is: Do I need to take Rocky Mountain like precautions already there?
In the Rockies the valleys are very limiting, so that the roads and railways share the same tight corridors as wildlife. Northern Ontario and Quebec are wide open wilderness where wildlife can roam freely with fewer obstacles. I find the likelihood of seeng wildlife much higher in the Rockies and almost a guarantee, whereas you can do a long drive on the main highways here and not see a large wild animal. I've lived 35 years in Ontario and done a lot of wilderness camping, and I've only seen bear along the road maybe 3 times.