I'm actually super surprised Georgia hasnt already moved to retake South Ossetia.
No can do. The majority of the people there do not welcome the Georgians.
That is what started that mess in the first place; people rebelling against their Georgian overlords. Depending on your world view, Putin either took advantage of the situation or liberated the ossetians. Or both.
Either way, the Georgian military would have to fight not only the russians still stationed there, but also the locals. And they run the very real risk that Putin will simply take Tbilisi at the end.
It is my belief that Putin sped up the negotiations by showing that it would be easy to capture Tbilisi. Georgia folded and two regions are still in play (Abkhazia is rarely mentioned, but my Georgian wife says Georgia have no control there). I think he wanted to repeat that strategy now, but met with a more substantial opposition. Georgia was burdened with a weak president (these days a jail bird), but Ukraine seems very different in this regard too.
There are fundamental issues at hand. At what point can a group of people secede? Why was it okay for Taiwan to secede from China? Why was it not okay for Catalonia? Why was it not okay for South Ossetia? Why was it okay for Kosovo to secede?
That leads to the question of what happens after mass migrations. Is Abkhazia a muslim region? Since when? Same goes for Kosovo. First dibs? Majority rule? What?
It seems NATO and Russia both answer these question depending on what gives them a chance to expand their territories. The Swedish diplomat Carl Bildt, to name one, had opposing views on this. It would be interesting to watch him debate himself into a corner.
(Either way, Putin needs to stop his aggression -- the situation became too messy the minute the idiots shot down that passenger aircraft back in 2012 or so)