If you are prepared to carry your own luggage off the ship you will get priority and be off by 7:00am( ship should dock by 6:00am ).Alternatively you disembark deck level & depending on which deck it could be as late as 10:00am.
We have done this twice. The first time we had checked into our hotel near Central Park by 0900 - everything was amazingly efficient! However, the second time it was raining and it was chaos. You should be ok if you have prebooked a cab though. Have fun.
Do we need a Visa for our QM2 trip to New york. Or is our British passport good enoug.