I too feel this pain acutely, to combat it I wrote a small and VERY basic JavaScript file a while ago to change this on the fly on a webpage based on your GeoIP location.
https://github.com/MartinMcGirk/English.JS
https://en.wikipedia.org/wiki/Member_states_of_the_Commonwea...
The key cases I think are cheque (vs. check), colour (vs. color), and neighbour (vs. neighbor) and "fuck" is none of those.
Or you could sign up for an open source account at http://crowdin.net/ and just let us do it ourselves.
It didn't really give me enough detail on Canadian English to create a new category there and then though so I left it as a "I should get around to looking this up soon".
My apologies to the fine people of Canada. I'll look at rectifying it shortly.
You know the way to our hearts. Personally, I think defaulting to Commonwealth is sufficient for Canadians. On a side note, does it pluralize "octopus" differently by region? I've always been a big fan of "octopodes" as the plural, which is not really accepted anyways.