“Dang! We’ve only got about a thousand years before we have to get our affairs in order.”
According to what I’ve read, Yellowstone is overdue - so, no thousand years - better get busy quickly. Don’t forget to put in several years worth of food and water for each person - perhaps as many as twenty years before there would be anything to hunt or fresh water to drink. Most surface structures out to several hundred miles of it would be flattened by the weight of the ash - so go low.
I really didn’t think I needed a /s. :)