That's what I thought too. For most U.S. carriers, Canada and Mexico are not considered international for upgrades and lounge access purposes. Use it as a rule of thumb. However, you never know. I won't be surprised that some actually can access lounge when flying out of Canada but it may be just pure luck unless you can pull off an Empress, that is getting access to lounge virtually everywhere even in SIN to SQ's Raffles Class lounge using a Star Gold status [which in theory is not allowed].