Maybe this is the premise behind the whole billionaires in the bunkers mentality. No one can bunker down indefinitely. But it might be possible to ride out the initial wave of hysteria, which will be insanely dangerous for any civilian caught out in the open.

I used to be full scale doomer, but now think if nature plus human nature quickly knocks out human CO2 generating capacity, ecosystems and whatever bands of highly resilient hunter gathers remain, might have a shot at rebuilding a decent planet. Even if it takes a mere 200K years to recuperate.