Here's how this is gonna play out IMO.
Ua will continue to reclaim territory until the hard Winter weather sets in - then things are likely to halt until the Spring
This will allow Russian regroup and form some sort of a cohesive defence - However the West will continue weapons shipment and training so Ua will re-start offensive in the Spring.
After initial resistance - the old problems, morale, supply, control command will begin to affect the Orcs again and Ua will regain more territory.
Putin will then have to play his last card - nuclear blackmail.
However, it's up to the US/NATO to tell Russia, in no uncertain terms that a nuclear strike is unacceptable and will lead to massive retaliation - spell it out.
Ideally, Ukraine should be allowed join NATO but with the likes of Turkey and Hungary - it is unlikely to be fast tracked. NATO membership is the only effective deterrent
