Majors cancel lots of flights over Xmas...right up to Xmas. Bookings usually are down, staff costs are up, crew shortages get severe, and it's often better to close up for a few days. Ground transportation is also severely limited, so they're minded to give up or severely scale back ops. They all do it. You are lucky to know so far in advance. It's the western world major holiday. You may be happy to fly over it to benefit from cheaper fares, but it is making the employees lose their major holiday day! All to provide a not-overwhelmingly important transportation service!