I don't see why you can't take your Locker on the cruise with you. Lockers go on DCL cruises all of the time...Lockers like cruises, too.
The only advice I give Members is to be careful with glass. The DCL luggage handlers are gorillas and I suspect the Carnival luggage crew is not much better.
If you don't want to take your Locker on the cruise and you'll be passing through Orlando by car or plane, contact me through the OL site and we can discuss how to coordinate a delivery and pickup.