I have not explicitly explored how U.S. gaps could impact Canada, but the U.S. faces gaps in domain awareness, in communications, in accessing the region and in some ways also communicating these challenges. Given that the Arctic is an area of such historic co-operation, where there are search and rescue needs, among others, that require international co-operation, I would imagine that gaps in any Arctic nation's ability to operate in the region would affect all.
On November 26th, 2018. See this statement in context.