- Hard to reach by land (not vulnerable to migration waves)

- Not so small there will be incredible deprivation if sea trade volume plunges (this rules out the vast majority of island nations)

- Not badly overpopulated

- Correct latitude (not too close to the equator)

- Stable liberal democracy (so they probably won’t take all your stuff)

- Unlikely target for outright conquest in great-powers games or expansion.

Bonus points:

- Interesting, varied natural environments.

They are indeed thinking about this stuff. It’s why so many are buying New Zealand citizenship and buying land there (and sometimes building their survival bunkers there too). It checks every single box, and basically nowhere else does.