I also went to Disneyland on 13th. Unluckily(maybe lucky) all tickets are sold out when I arrived because I didnt book the tickets. So We just drove to Hong Kong Disneyland Hotel and have lunch there.
Finally, I went to Disneyland yesterday because it was my daughter's school holiday after exam. It was pretty empty. Many empty tables in restaurant We can even get into 巴斯光年 straight away without lining up or getting Fastpass. My daughter enjoyed it so much and we had a good time.
I think the reason it is not busy during this period is because many students are still under examination and many people wants to take a rest just after christmas/new year holiday.
So if you guys want to go Disneyland, I think it is a good time to go now :-P