The bigger question is, can Russia sustain operations for any length of time? More recent history tells us the answer is no.
Probably the reason Russia hasn’t invaded the rest of Ukraine. But, who would want it?
You are correct concerning Russia's logistical abilities. The real question though would Putin need to sustain an offensive operation? With our current leadership on both sides of the aisle, would the US (NATO) even begin to fulfill their treaty obligations of mutual defense other than sending a strongly worded letter to the Kremlin?