Considering the degree of popular discontent with the invasion in both Ukraine and Russia, and the depth of the sanctions against Russia, and how complete the unity within Ukraine against the occupation is, this would like be one of the easiest wars ever to win with simple nonviolent resistance.
Let's say Ukraine just stops fighting right now and Russia tries to occupy, but they refuse to cooperate with the occupiers. Then what? The Russian soldiers don't even want to be there. They'd want even less to violently enforce their will over a population that isn't resisting. The Russian people don't want their soldiers to be there, and they want their to be there even less for a long drug-out occupation over a nation that isn't even fighting back. The Ukrainians would be united in their resistance. The occupation would be incredibly costly for Russia cause Ukraine is a huge fukking country so they'd have hundreds of thousands of forces who would need to be supplied continuously, and meanwhile the sanctions would be incredibly costly for Russia too. The Ukrainians would simply tell the world to hold strong on the sanctions and tighten the noose on Russia's neck. Every day it went on would be like a continuing war for Russia with all the resources they'd be hemorrhaging but they wouldn't even have a way to fight back. Eventually they'd be willing to sign a peace deal better than anything they'd off now solely so they could bring their soldiers back and end the sanctions.
Two issues
The Russians conquered the Ukrainans at least 3 times before.
Secondly you're assuming that the Russians will follow the rules of Law Warfare which wouldn't even apply during an insurgency.
I was in Fallujah during the aftermath of the battle and there was a 10% occupation rate tons of buildings were destroyed, If the building didn't have an X on it meaning it was "cleared". It wasn't standing. I knocked down the wall of a house with an X on it by accident while test driving a Tank.
The Marine tankers said they needed a Lt. Colonel's approval to fire the Tank Gun.
You think the Russians will tell their troops that? You think that a ünmotivated" Russian solider will be in a armored vehicle see some dudes shooting at him with an AK or throwing a Molitov Cocktail and wheel the Co Ax Gun (the light Machine gun) at them or will he fire a Main Gun round that will kill them and destroy several houses full of innocent people? That's not what the Russians did in any other war.
The only reason they wouldn't do that is because they think that NATO would intervene which would mean that the Russkies were disiplined which means that they are somewhat motivated.
What does Victory look like for the Ukrainains? A devastated countryside with the Russians taking everything they can
and the 82nd Airborne in the Donbass. If I were Russia I'd play up the fact that It will be like Germany Black soliders will be fukking the shyt out of broke ass Ukrainan girls.