I think the other NATO members would be more than willing to sacrifice Canada if it meant that the hunger of the US Beast would be satiated temporarily. Canada is already half way into its maw anyway. Europe does not care about Canada, they also see it as "the 51st US state". The only reason it hasn't taken form yet is the theatrics of liberal democracy. But, attacking the Great Europa™️ would be an act way over the limit, as Europeans see themselves as temporarily embarrassed empires, on equal footing but dependant on the US empire, a relation that they despise.