Or we could, you know, build tougher buildings instead of going extinct. Or move to places with milder weather instead of going extinct. Actually--some people already live in those places; we just need to not all kill each other while deciding who gets to live there.

It would be calamitous and/or expensive, sure. We should avoid it if we possibly can. But it's not an extinction-level event like a KT-sized impactor.