Well, you don't tell us your rig or gross weight. If your under 10,000 lbs you don't need a CDL. Yes, there is reciprocity.... if your legal at home you'll be legal in most provinces. However.....
Customs will not check your weight or licence when you enter Canada.... they are not highway enforcement/MTO.
You may be stopped and checked on the road by the local Ministry Of Transportation people.
If you are in an accident and are overweight or under licensed, the insurance companies will come after your and fry your assets.