I'm guessing that the St. Catherine Apple store will have the most stock and the biggest line outside.
I've been trying to find a webcam pointing down St Catherine street but the closes I found so far is near Peel.. Too far to see the Apple Store!
If you can get to Fairview you would have more options but they might have less stock - and you won't know about stock until whichever place you choose opens.
Nobody really knows until Friday morning!