In Toronto off hand, I can think of 3 places for indoor CQB games (TTAC3, CQB Paintball, and Defcon Indoors but I'm sure theres more) and each usually has a good turnout winter or other wise.
I've never gone to any airsoft games in BC so I didn't vote nor can I offer an unbiased opinion. I like TTAC3, Brian runs very nicely structured games and he always changes out the layout so regardless how often you go, it'll look different but its small topping at around 16 people depending on the scenario being run. CQBPB is a larger multi-levelled field that does 30 players easy with a very challenging layout but the only issue I find is because its a paintball field first, the place gets messy. I've never been to Defcon but they have both an indoor and outdoor field.
"Hey I'm the first one to say its a great country but its a straaaaange culture. This is a place where gun store owners are given a list of stolen credit cards but not a list of CRIMINALS and MANIACS. And now they're thinking of banning toy guns...AND THEY'RE GONNA KEEP THE F**KING REAL ONES!"
-George Carlin 1937 - 2008 (RIP buddy)