There is vast difference between just driving somewhere and actually controlling it. Russia learned that in first month of the invasion. If they weren't stopped at Voznesensk, they would be stopped somewhere else - there was singular BTG driving somewhere deep into hostile territory.
I don't believe they'd be able to keep and reinforce it, given that they were only able to bypass Mykolaiv due to the early day chaos. And Mykolaiv was giving rest of russian forces there enough problems.
However, at this point it's only speculation, probably not worth getting deeper into it.
Another example of BTG driving deep and getting decimated: https://www.youtube.com/watch?v=4g68MmLrGvM