Kind of agree with you, nothing can be taken for sure right now.
Regarding the exact nuclear strategy to be used, I suspect better brains are thinking about this already, but my take is, they'll go for intimidation. Blowing up a tactical, somewhere in Ukraini, in the middle of nothing. Then they'll just ask for Zelensky to hand them an unconditional surrender ...or else.
I think that after having watched a nuclear device gone off inside your country, few will remain confident they could avoid being obliterated without warning.
I know these are harsh words, I'm just trying to state my opinion very clearly. Hope you all guys there keep kicking it.