Originally Posted by
gglave
I don't know about YUL, but at YVR this would be a fiddle. If you choose not to board its not easy to just leave the secure area - At YVR you need to find someone to open a door and escort you to Canada Customs & Immigration, then you need to talk to them to exit.
Same thing at YUL.
(I was doing hidden city and wanted breakfast so I went to the US just for that; client wouldn't pay for it so that's why I had to do that)