Interesting question, you might want to post it on the Canada forum. As I understand it there is some lat up north where it all switches to to true north as magnetic is totally skewed. I know for a fact that at least one airline up there purchased a fleet of TP's that could not accomodate this and the planes were essentially useless for IFR. (Unless you cheated and used your handheld Garmin etc but that hey that never happens)
I'm guessing that they do have this covered as a lot of the transpolar routes are on the triple.
20driver