The military situation appears to be near a short-term draw on both sides, with Ukraine having initiative. However they burned through a lot of their reserves and ammunition stockpiling/expenditure of western weapons. If Ukraine scores another operational victory the Russians may escalate with chemical and biological weapons as currently most of their army is rebuilding in Russia. It would really surprise me if they use tactical nukes as that's not their combat doctrine.
All of this is due to Russia's pullback of their army in July. They are preparing for a winter offensive as they integrate 300,000 reservists and gathered tens of thousands of volunteers. If this offensive comes this winter my guess is that it will be late, maybe in 2023.
The Russian strategy appears to be that they want to be successful in the defense while deploying the minimum of forces in the Ukraine. They want to wear out the Ukrainian assault reserves and western weapons, and by the time the Russian army returns they will have weakened their enemy while having an army 2- 3 times larger than the one they invaded the year before.