The tolls on the NY thruway are a killer - that is the disadvantage of going through the US - but the gas and camp fees are much cheaper - so it is a decision to be made.
When going to Quebec City, consider staying on the south side of the river and taking the ferry from Levis to Old Quebec. Parking is right at the ferry docks and is reasonable for the daily rate - also lots of campgrounds not far from the docks. It is a very enjoyable area to walk around, have lunch and/or dinner at a sidewalk cafe, etc. Most restaurants will have English menus so at least you know what you are ordering. For the most part, language in the tourist areas is a non-issue.