The port of Churchill at the start and stop of navigation regularly sees ships coming in with ice damage from the little trip into Hudson's bay. Churchill works currently because it is the closest salt water port for a sizable region of Manitoba and Saskatchewan. Shipping from there saves a great deal of rail freight. The insurance for ships travelling to Churchill is high. For the NW passage or the Arctic Sea routes to be seriously competitive, insurance rates will likely need to be much lower.

I also suspect a greater number of ships designed to deal with the ice will be needed. I am not talking about ice-breakers. Ships with specially reinforced hulls are required in northern water to deal with those waters' icy conditions.