Is it possible?
What are the hurdles when it comes to player base?
1) Start by eliminating any players who's sole interest is skirmishing or light milsim (single day long scenario with breaks, for example).
2) From the remaining players, eliminate those individuals without the resources or motivation to attend an event like this (say, the 16/17 year old age bracket and those unwilling to travel long distances for an event).
3) From the remaining people, eliminate those who will not enjoy the scenario you're proposing (a Vietnam themed event won't attract the modern SF impressions, and a modern Iraq event won't attract the WWII component).
4) From the remaining people, we cut out those who won't be able to attend due to work, personal issues, or flaking (avg about 25-50%).
If from that, you can still pull out 10-15 people from each province... then you only need to make a good solid event. The reputation of a good host will help as well (and I know you have that). In all honesty your events that you've held in the past are more than adequate to get the player count. What you need in addition to the event is a method to gather interested parties from the said pool of perspective players and get them to your event. Setting up a regional host for example?
Someone in Toronto to organize a Toronto contingent. A Vancouver individual to organize a Van City contingent. Perhaps these people should have travel arrangements ready to go? A 'buy in' price perhaps for interested people? Pay 200$ and all your travel/accomodation is included (even if it's in tents).
Seriously, your events are more than acceptable for a 'Canadian event', you just need to get people there. That's the only difficulty I see.
"Solving an imaginary world's contrived and over dramatic problems... 6 millimeters at a time."