You don't say how you will be arriving ... so ...
When I did this for my youngest son a few years ago - I had all the plans, etc done while I was at work and sent to me there or to my PO Box that he couldn't get to w/o me1 He knew nothing - and didn't catch me packing bags and hiding them the nite before. It didn't dawn on him the dog wasn't in the backyard when he got home, so it was good to go! Had my parents show up to take us to the airport, but since we snuck OUR bags into their trunk, we told him we were taking them to the airport! LOL! He had no idea as we had done that a few times before!
Imagine his surprise when we go to the trunk and he see the bags WE use - hehehe - then is confused about what is up! Had no clue until the ticket agent mentioned Orlando! I t hink he flew higher than the plane!