>I'm not sure if the bolthole idea is referring to an escape for EAs in particular or relocating as many people as possible in general,

Perhaps "bolthole" is not quite the term I'm looking for, at least in the sense of primarily being about relocating individuals. Rather, I'm using it as a catch-all term for all "post-apocalyptic" preparations. A seed bank and/or data bank located in New Zealand would be good examples. 

Living in New Zealand, there appears to be a near-consensus that it's one of the best places in the world to be in the event of a nuclear war and/or nuclear winter. So from a personal perspective I'm pretty well-optimised.

From an EA perspective,  however,  I've wondered for a while about the cause area of an "NZ bolthole for x-risks".  If New Zealand is indeed likely to come out relatively well in the event of many disasters, then it seems there could be significant value in investments that have high value in some of the more likely scenarios.

 This hasn't got much beyond some idle chatter with other EAs, and I'm quite uncertain as to exactly what the highest value investments would be. I think exploratory research at least is warranted. 

However,  with the Ukraine situation the question (at least with respect to nuclear-risk) has suddenly become a lot more time sensitive. Rigorous research may produce answers too late. What low-cost (>$1,000) actions could we in New Zealand take that would have an outsized impact in the event of a nuclear war in the next 3 months?