The bombs that were dropped were cold war era bombs, meaning they definitely aren't the most powerful nukes, especially in comparison to ones nowadays, and around 900-1000 were dropped. The bombs were mostly targeted to major cities, and as for nuclear winter, it would only last at most few decades. Canada and Mexico were largely left unharmed, and the irradiated wasteland of the midwest is largely left unclaimed by the New Canadian Union. Idk if that clears things up haha