We enjoyed our trip about four years ago, in a rental car. South shore going east and the North shore going west from Quebec city to Montreal on the way back from the maritimes. No trouble with language; only one or two occasions when I wished I had finished French in high school.
I found people quite friendly and there was even an epiphany between this unilingual Albertan and a Francophone hostess at a Parc National. While knowing that a Parc National was not a federal National Park, I tried my national park season pass just to see what would happen. It wasn't excepted, but the striking thing was that the lady was embarrassed about it, obviously thinking this Anglo was getting a raw deal. That's when I knew the separatists were finished.