The RU troops are not fighting for anything they believe in. They know they have been lied to. Ukrainians have the home-field pissed-off advantage.

And, Yes,

This is very much a signals intelligence war. Not just the Command and Control stuff, but the calls home from soldiers. And remote sensing. Me thinks there are some real time cat eyes up in space.

What's next? Continue to cut and control surface supply routes.

The thing about the Crimean Peninsula, it only has three surface access points. One bridge to Russia proper, the other two to Ukraine are narrow corridors over salt/tidal flats. Be a shame if any one of those became unusable. (I've heard rumors of civilians leaving?)

ADDENDUM: POW's may become a serious issue.