We were there Dec 16-19 as well... and availability was pretty good when we booked.. but the reason we were there that week was because just two weeks prior there was NOTHING available. AoA was busy, and the parking lot was plenty full. Parks were not empty.. but not super busy either. More busy then I would have thought one of the last 'quiet' periods on the calendar were supposed to be. I think TP was calling for about a 4-5 average a few months back.. and it ended up being more a 5-7. TL
R - they were busier than I thought they would be... but still very manageable. Saturday tho was another story of course..
Remember, after thanksgiving before xmas *used* to be one of the quietest times of the season... as was late Sept.