I've done it before.
As long as you are employed by a foreign company, and have completed an IFR renewal on a foreign licence in the past year, then you don't have to rewrite your Canadian exams etc, and your Canadian renewal is just treated as a normal renewal. I can't remeber what the legal reference is, but it's ther in the airlaw (and you have to note the legal reference on your forms where it asks for reasons for deviations from the standard procedures). Transport Canada are very understanding like that! Sensible rules.