There are cloning facilities (among others) underground in tunnel networks across the USA. I have no idea how extensive they are or what all is down there, the most optimistic guess is FEMA had a better disaster preparedness plan than camps and there's a load of hydrobeds, seeds and bunkers ready for us down there. I'm great at optimism.

They've alluded to it in media for a while, most memorable was that Hulu ad campaign they ran about all celebrities and actors being literal aliens here to eat our brains. Remember all the 9/11 stuff they ran ahead of time to prime our consciousnesses to accept it? There you go.