IMO 95% of the people working on cars at Canadian Tire are idiots! I wouldn't let them check the air in my tires.
If you're looking for some winter tires, I'd suggest looking on the local used sites. Lots of good deals to be found on some nearly new tires. I found a set of 4 winter tires on rims for my wife's car, they were previously used for 1 season for $360.
they were worth close to $1000 new.