The cost to take guns into Canada is $50.00 if I remember correctly, you are allowed I think 2 or 3 guns on each sheet. Also make sure you have a custom form to bring back your guns to the United States.
As for hunting with iron sights, yes it can be done, but you will run out of light early in the deep woods, and that is the time most bear come out. But if you are going to have a back up gun with you with a scope, that would work.