I don't think anyone knows but so far all of the boarding groups have been filled by 8 a.m. Since you are going at a much busier time, you may need to plan to be in the park much earlier.
Currently when the park "opens at 9", the park has been opening about 6:30 due to crowds and the BGs are filled before 8.
I would agree, about 5-5:30 at the latest seems about right given the crowds that time of year.
Our Authorized Disney Vacation Planners are here to provide personalized, expert advice, answer every question, and uncover the best discounts.
Let Dreams Unlimited Travel take care of all the details, so you can sit back, relax, and enjoy a stress-free vacation.