It amuses me when people discuss dismembering Russia, forgetting that Russia has the power to turn us all into shadows on the wall and wouldn't hesitate to do so in order to forgo that outcome. While there are some unrealistic elements of the peace plan broached in the topic post and others in this thread have done a fine job of pointing them out, I do appreciate that it recognizes the need to give Russia an off-ramp that would discourage taking a nuclear option. I voted "yes" on the poll.
the only way the Russia Federation is dismembered is due to internal collapse, which is not something they can prevent by using nukes, and while unlikely it's not an impossible scenario.
The most likely forms of internal collapse (e.g. military coup, assassination) would realistically rule out such a scenario, since there would still be people at the switch who are extremely committed to not letting Russia fall to an enemy that openly wants to destroy it. It's not strictly impossible, but it seems closer to Alien Space Bats than to anything feasible.