Booking ahead in the Philippines?

Hi everyone,

I am coming to you because I will be going to the Philippines for 32 days in December (early December to early January). I usually enjoy booking 2 nights and then rolling with it, but I am getting scared by all the people saying you need to book flights and ferries ahead, especially during Xmas period. Could anyone who has travelled at this period confirm if it was hard to book domestic flights 3-6 days ahead and ferries 2-3 days ahead? I would love to stay flexible and be still able to change locations if it's too crowded. Thanks for your help!