Kate, I believe you might want St-François-du-Lac near Baie-du-Febvre (Yamaska County) if that parish is officially named "St-François-de-Sales". This is on the south shore of the St-Lawrence, not far from St-Jude either in the neighboring county.
Another one is St-François de Sales on Ile Laval (north of Montréal and not far from l'Assomption) on the north shore of the St-Lawrence. Good luck in your research.