Seems to be to defend from behind the Dnieper River and pound anything which looks like electrical/water/medical/communication infrastructure to prevent the Ukrainian population to be able to survive the winter. At the same time, they are “training-in-place” their 300K new conscripted and using them, in conjunction with massive artillery barrages to try to re-take territory on the eastern front (north of the Dnieper fork (while maintaining the threat of an invasion from Belarus to the north).
The West has continually underestimated the quantity of missiles, drones and artillery shells which Russia has available, so their potential ability to maintain this pressure through the winter should be concerning.
Russia has maintained a level of deterrence on the West which prevents them from supplying offensive weapons capable of reaching Russia’s major cities from Ukraine and has escalated their level of destructive retribution each time Ukraine has hit a target in Russia-proper or Crimea.
Ukraine has proposed a peace based on Russia pulling back from all Ukrainian land (including Crimea) which amounts to a full defeat. Russia may have strategically withdrawn behind the Dnieper in the south but that is far more defensible and has the potential to take the offensive initiative in the north. In the absence of significant disruption against Putin within Russia, there is little chance of them agreeing to what amounts to a defeat at this stage. The Russian position is that Ukraine should hand over rights to a third of the country to Russia.
Taking significantly more ground during the cold of winter is probably not in the cards for r either army and the current scenario seems to mean that the Russians will continue to level Ukraine with high explosives until spring flowers start the tug of war on the ground again.