I visited Quebec at one of the craziest times of the year- January. I remember walking the streets and the temperature was -40 C (including the windchill). I loved the every nook and cranny of the city, its just too bad I wasnt able to explore the city walls because of the snow. Check out the Musee de Amerique-Francais in the old Seminaire (?), though slightly propagandist, is one of the best introductions of the history of the French in North America.

Not on the WHS list but its also worth checking out the Isle de Orleans for a slice of provincial Quebecois life and tasty maple butter spread!