I am talking boots on the ground. Russia will not give up control of Crimea sans all out war.
If Kherson falls and a few other important links, that might mean being cut off and still nominally holding onto Crimea. It becomes a naval and land battle to lift a siege, then. If the then-beleaguered garrison of Crimea doesn’t hold on and surrenders, that’ll be like the final British defeat at Yorktown.