@Atlas, I'll assume that is a rhetorical question and not a capitulation.
Underground bunker, 2-3 years food stock, expect a "nuclear winter" climate. Scavenging lifestyle using the remains of our current civilization and working to rebuild. These scenarios have been presented in both book and movie formats.
I think some would survive. It has happened before, but life survived. I really hope it is not a bunch of our politician in their air-conditioned bunkers, but that is why they were build...
Yes, there are some events which the planet might not survive (nova of the sun) but they are not as likely as a meteor strike. I'm trying to remain optimistic. Not that I look forward the that lifestyle, but the alternative is even less appealing. I don't want to be "Otzi", discovered under a glacier by the next civilization.