Given time and if the projects are not dropped, the Canadian and US Codes will say the same thing. An electrician or lineman will be able to go from one country to another and just learn the local differences the same as from state to state or city to city. For what its worth, Mexico uses the NEC but not the current version.
OK, but there is hope. I understand that New York City uses the NEC (millions of local changes but the NEC never the less). I wonder if anyone can verify that statement for me?