I doubt you will get anything from the hotel because the room is unavailable in Marriott's system no matter what. They will get paid for it and cannot rent it again, so why would they give you something else.

I do the 5th night free all the time to get an 8pm late check out. Just load your car and head out without saying anything to them. If asked, just saying you are loading it in advance since you are leaving very early in the morning. Never had an issue

Unless you are showing up at 5am, its better to book it an extra day so you dont risk any issues