You don't want to be on a cruise ship anywhere near a hurricane. In August 1998 DH and I cruised from NY to Bermuda and left Bermuda the night before a hurricane arrived (can't remember the hurricane's name). That storm was not nearly as big as the one headed for Florida. The whole trip back to NY was terrible - most of the ship's entertainment was canceled, everyone had to stay in their cabins (not that anyone wanted to go out anyway - everyone was sick from the rocking ship). Even drinking from a glass was nearly impossible - that's how much the ship was rocking.
I would definitely try to cancel instead of doing a cruise to nowhere, especially if there's a chance you won't even be able to enjoy the ship's amenities.
I would definitely try to cancel instead of doing a cruise to nowhere, especially if there's a chance you won't even be able to enjoy the ship's amenities.