There's a 10 page thread in the technical support forum about how over half of the Canadians playing wow have unbearable latency from 7-11. Blizzard responds to literally every other thread in that forum yet ignores the 10 page CANADIAN thread pleading for help.
I'm not aware of the functionality, or better yet a reason to use a function, that would block connections to the game from a specific place. Usually when these issues occur there is a broader failure of internet routing.
Personally I love Canada, what with your syrups, hockey, export of hilarious comedians, and... other things.