Thing is, he already had access to the Black Sea and the Med after 2014. Not total undisputed control of the Black Sea, but Ukraine was in no position to challenge him on the sea, so for all intents and purposes, if that was his strategic goal, he had accomplished it, and is only risking losing that by waging this war.
A well orchestrated plan getting refugees out - even our nato military was helping..so this was in the works long before Putin went in.