I wonder how many troops Russia is mobilizing for this Donbass offensive. Some pro Russian sources say 200-250k. I really doubt that. It would be logical to mobilize that many forces for this but I doubt that’s the case because Russia mobilized 200k near the borders before this war.
Now the reports always have been half of Ukraine’s military is in the east. That doesn’t only mean the Donbas. That includes garrisons in the major cities as well. The Donbas has anywhere between 65-120k fighters in the pocket according to reports.. In any rate Russia and allies need a massive numerical advantage to get the offensive done.
After withdrawing troops from the Kiev front it will; in the most logical and economical way possible with respects to Russian infrastructure; take several weeks and will at most contribute around several thousand soldiers and a few dozen armored vehicles if they choose to allocate those forces to the east, they will at the very least keep a relatively strong force in Gomel for further limited operations and for defensive roles.
The Russians have already allocated an estimated [100,000-200,000] for operations in the Ukraine; it is unlikely that there is even half of that number currently deployed in the country given the lack of military infrastructure available for the housing of troops, therefore it is likely that only a few dozen brigades and armored battalions will be allocated to any new offensive given heavy resistance by Ukrainian forces.
It is likely that Russian Forces will shift focus to intensifying bombardment of key military positions and infrastructure while mopping up any pockets of Ukrainian Forces within held territory; we’re seeing a considerable slow down of Russian Forces and given the shift in RuMOD policy in regards to the Ukrainian Campaign it is likely that they will shift in strategy to an overall policy that is more comprehensibly defensive in nature.
This however is all just speculation based on available data; we will simply have to wait and see.