Nah, most of these people are overconfident narcissists, they play it smart economically, but planning for that kind of future isn't in their playbook. Their superbunkers will fail as everything else does. We haven't had enough really put into researching a self sustaining facility that can actually operate for years, most of what's sold is snake oil. Whatever billionaires might be paying for that'd be under wraps wouldn't be enough. If arctic bases require supplies to be shipped in, if the ISS is the only real out there place we've got and it also needs rockets shipping it stuff every couple of months, the elites are screwed. If the US hadn't given up on the space race because they already beat a goal they themselves set, we might have had the tech to reliably grow food in an enclosed environment, recycle every single resource, but in reality the billions stopped coming and there hasn't been real advancement on this shit for decades, not in a way that'd let you survive SHTF for more than a few months if you've also got a bunch of people who would be willing to screw you over, at least not in most billionaires cases. You might have a handful that'd get lucky, have actually stayed hidden and stockpiled enough non perishables to live the quality of life of someone from the lower classes before the world ended. But they'd be wanting to off themselves with how their luxuries have disappeared