I was going to say that Canadians probably wouldn't get the reference unless they were were actively pursuing British TV shows and entertainment, especially pre-Netflix/Hulu, because the US Office never got airtime up there. But they did get the British Office, which I guess makes sense in a way come to think about it.
It was definitely on some cable channel here in Canada, I watched it and bought the DVDs after. Don't know if it really had a lot of viewers here or not. Ricky Gervais stand up show instantly sold out when it went on sale, but I never hear anyone reference his version of The Office.