We were staying onsite this weekend - just got home tonight - and we were at the MK at 745 today. They'd were not checking for hotel keys for onsite guests by that point, and anyone could walk in if they turned the Mickeys green. In other words, rope drop may be a few minutes before the official time.
We went right to Buzz and rode three times, then did a ride on Speedway, Barnstormer and Teacups (twice) before heading to the Jingle Cruise, all by 930 but then it started getting busy. By 130 there was a line for the People Mover and a 40 min wait for the Laugh Floor - 125 min for Space Mountain and 7DMT. So we lunched, used our fast passes and played a few rounds of Sorcerer's. It was never hard to walk around but the lines were more massive than I've seen them the weekend after Xmas, and this was our 4th year of it.