It depends on where you want to dine and when. We are going 12/9 -12/15 and I had no trouble getting all the ADR's I wanted. In December I do make our ADR's very early all are for 5:30. This way we have dinner then visit the parks at night when everything is lit and beautiful. Because we have dinner early, by the time we get to the parks they are empty because most people are dining or at a show. It's fun because we skip dessert, walk off dinner and get a holiday treat in the park. You also get the best of both worlds, since 5:30 is usually the earliest ADR, there is no waiting. The restaurants are quiet and half full.