Yes, of course my scenario assumes that I'm not killed or incapacitated such that I can't carry out any plan to mitigate possible fallout effects. And yes, I fully expect the Russian nuclear arsenal to reflect the overconfident recklessness we've seen in Ukraine. I also have an additional advantage, living in the southern U.S. - a nuclear strike from Russia would be largely directed over the north pole, so any ICBM defense system has even more time to intercept before something lands here.

I'm actually not living within the outer circle of your 550 Kt, center-of-city target. Sure, I'd expect to probably die within a few weeks due to societal collapse, but that doesn't mean I'm not gonna wait out the fallout for a day or two, throw my kitties and wife into our car (along with the extra tanks of gas), and do my damnedest to keep us all alive as long as possible. Knowing, the whole time, that by the end of our rope, I'd probably have preferred us to all have died in an airblast. But I'm a stupid human with survival instincts, so. I'd probably head towards one of the spring-fed headwaters of a nearby-ish river, before anything else. Like constructing a rad-hardened, thicc af glass greenhouse? No idea. God, what a hellish scenario.