So just an update... Got back from Montreal yesterday. Went to La Casa del Habano as suggested above and it was great. HUGE selection, friendly service. Got everything on my list.

Got to YUL yesterday and found that they DO now have Cubans cigars in duty free after you cross the US pre-clearance. He said it's not listed on the airport website yet, as they just started carrying them in the last few weeks. Selection is limited (there's a small humidor) and it's all boxes - no singles. But I was able to buy 3 Montecristo cigars for the price I paid for 2 in downtown Montreal. 94CAD for 3 MC #2. 175CAD for a 10 count box of Montecristo #4. Also had H Upmann, Romeo Y Juliet, Cohiba. Just limited selections of each.