There are plenty of restaurants both on/off property that offer special Christmas menus. Your best bet for on-site menus is to check the disney site and also allears.net for menus. For those that are off property, there are many amazing options and best bet is to do a search on "open table" for whatever kind of cuisine you are interested in. The restaurants on open table usually list menus to view.
Any other questions, please feel free to ask. I live in Orlando and have worked in restaurants on/off site for the past 15 yrs.