The Front Desk is staffed 24/7, so you'll be able to check in no matter how late (or how early) you may arrive. Your room will be there waiting for you regardless of whether you choose to utilize on-line check-in or not, but on-line check-in will stream-line the process and perhaps get you to your room a little bit faster in the wee-hours of the morning on November 20.
Since your plans have changed, I would make sure to call (407) 939-7675 and note the late arrival on your reservation.