They will try to buy their way out of it. On an individual level. Water shortage, they’ll pay more for water. They’ll pay top dollar to keep the a/c on, etc. when no amount of money will help and they didn’t plan ahead with Zuckerberg-style bunkers, they’ll just die like the rest of us.

And the billionaires will possibly be killed in their expensive bunkers, if the Fallout series taught us anything.