Canmore, Alberta. You're minutes from all the places that make up 90% of the Earth porn pictures on the internet, nestled right in the Rocky Mountains. Nobody is ever going to nuke, invade, occupy or otherwise come anywhere near Canmore during a war. Even if they did you could just escape into the vast Canadian wilderness which surrounds it. Lots of good food, shops, recreation and a generally great place to live and raise a family. Cheaper than Banff too!

Nobody said it had to be a major city.