Victoria-class submarines are not effective in the Arctic. I don't know how effective they are outside of the Arctic, but at the end of the day, I don't know if the military has a plan.
It's always a great debate in the Canadian Armed Forces whether or not we need submarines that can move under the ice, because it brings up this issue of nuclear, which I think frightens a number of people across Canada. My understanding is that you need to have nuclear submarines to be able to stay under the ice long enough to do what you need to do to counter threats and to guard your sovereignty, but I have not heard of any type of replacement programs for the Victoria-class submarines.