This comes up a lot, so much that I think there should be a sticky, if their isn't already, on the subject.
This is how it works when you're in the US and is likely the same for Canada.
When towing the law that governs are the laws of the state you are driving in. Same for the total length of your rig.
The law that governs what you can drive, i.e., class of license, are the laws of your home state.
So in simple terms, your home state controls you and the state you're driving in controls the rig when it comes to length and towing.
John (N6BER), Joyce, Lucas (Golden Retriever mix), Bella (Great Pyrenees) and Lance (Great Pyrenees).