I have the funny feeling you don't know what you're talking about. Imagine that. Some dude talking out his backside on the internet.
How many nukes do you think it would take to end the world? 40? 50? How many until there's nowhere to hide?

https://en.wikipedia.org/wiki/List_of_nuclear_weapons_tests

There have been 2119 verified nuclear weapons tests since 1945. There are a handful more that are suspected to have taken place. Since October of this year, both the United States and Russia have detonated 2 nukes each. As far as I know, I'm not dying of thyroid cancer. You?

In war, you're at far greater risk from a single person or small group of people armed with guns (invading soldiers, secret police, scummy people taking advantage of temporary lawlessness) than you are from nukes or fighter jets or Targaryens on dragonback. If you're looking for a spot to bug out, look for somewhere that will allow you to avoid contact with people, or a spot that no foreign power will care enough about to mess with, thus leaving the local society more or less intact.