You may not be able to use the valet for that time. Usually your flight has to be 12 noon or later so you will have to check that out. But if you do walk off and take a cab you shouldn't have any problem.
While it was a HAL ship, we did just that in January. I had up book on a 10 AM flight and we were at the airport by 8:05AM.
More than 300 days at sea so far with many more to come. (Actually more - one of these days I'll count them properly.)
Celebrity Solstice - Feb. 21/15 (moved out a year due to illness)
42 cruises - too many to list however cruiselines are in no particular order:
and some unknown tub
Yes, I'm a Royal Chump and proud of it.