The invasion of Ukraine was a strategic disaster for the Russians. Now they will try to reach a peace deal that crystallises their gains, even as they seem on the verge of losing them. They'll use nuclear threats to buttress their negotiating position. But Ukraine will rightly not accept the status quo, as they believe (as I do) that they will succeed in expelling the Russians and the nuclear threats are a dreadful bluff.
In the end, Russia loses Crimea and the Donbas. They don't have the economic strength to keep going. Whereas Ukraine is supported by the West, which can. And fingers crossed, we get a better, more friendly Russia after its defeat. The equivalent of what happened to Germany after World War II, when it finally realised that bullying and belligerence isn't a top strategy.