BioSehnsucht
Model 3 LR
I'm less worried about Ukraine getting nuked to "win" the war than Putin just going "F IT" and taking the rest (or at least, the west) of the world with him, if he can't have what he wants. If he launches nukes, I would expect his targets to be NATO members and so forth (perhaps prefering further targets to minimize collatoral fallout if he gets lucky and the west fails to follow through with their half of MAD). This would pretty much require a like response, and Russia would be ended as far as a functioning country goes, along with probably millions of dead elsewhere, and many other nations struggling to survive due to damaged infrastructure. Much of the west would end up decimated along with Russia, and I would expect in that scenario the US is hit too (unless our missile defense manages to shoot them down).I don't see a nuclear exchange in the works. Russia has too much to loose, first internationally; they will be a worldwide pariah, with a gutted economy (assuming other countries don't start lobbing nukes back, a thought too horrible to contemplate). Lets not forget that Russia is also downwind of Ukraine. Granted Putin has been behaving increasingly irrationally so I'm not putting money on that.
Hopefully he's just a psychopath and not a sociopath.