If by Quebec Provincial Library you mean the
Bibliothèque et Archives Nationales du Québec and the Montreal collection at the
Bibliomontreal site, they don't exactly keep their own e-books online (barring the
project to digitize Quebec-related stuff), but instead link to other sites offering e-books.
The Overdrive collections for Quebec seem to be at
McGill for that library, and via
eMedia for some smaller ones.