I’m highly confident this project will wrap up on time simply because Disney has way too much to lose by not hitting their holiday deadline when room rates are super high. We’re talking millions of dollars they’d miss out on by just being late 2-3 weeks. If you look at photos from the summer, you’ll see most of the rooms have already installed the cabinets, floors, dining table, murphy beds, and lighting. That’s pretty significant, because then they can focus on the small details in rooms and common spaces.
Also, I know the outdoor areas around the pool look like a complete disaster, but that’s the stuff that can be done the fastest at the end once all the cranes, lifts, and trucks are out. Pouring concrete, installing palm trees and flowering plants, mulching, and laying sod can essentially be done in a week assuming you have the proper manpower.