With this tech advantage what is there to stop Ukraine advancing into half of Russia?

Russia is a nuclear power, I’m not sure if they’ve missed the moment or the fact so much was spent on its upkeep it was a magnet for corruption and all the rocket fuel has been replaced with pipe cleaner.

The thing that really annoys me is there’s lots of great Russian people, and Putin has herded them off of a cliff. Where does Russia go from here, or can Russia go?

A myriad of warlords? The Russian East disintegrates and China comes in to reclaim the land Russia took after the Boxer Rebellion 150 years ago?

Manpower is the major resource necessary to take ground. You can bomb everything from the sky or from artillery far away but you don't control the land until you can put boots on the ground to defend it. Even if you manage to drone every Russian in Crimea, you don't own it until you can move in and defend your claim.

Many parts of Russia were independent kingdoms only recently. Probably (hopefully!) Russia will disintegrate into its smaller pieces.