Cottonwood
Roadster#433, Model S#S37
As a first SC in the Montreal-Toronto corridor it wouldn't make sense from Tesla:
Montreal Cornwall = 116 km
Cornwall - Toronto = +/- 435 km (not enough, by experience, to make it with one full charge, especially if it's raining or if the pavement is wet... worse when the snow will be there)
The Kingston has to be the one:
Montreal - Kingston = 288 km
Kingston - Toronto = +/- 262 km
My two cents that Kingston will be the next after Squa & Drummondville
I fully agree with your reasoning on what would be most useful. However, I still put my bet on Cornwall first!