I personally do not believe anyone should count on walk-ups during this period (even though you're talking about over a year from now). If there's a place you really want, or if you are going to be on the dining plan, you should probably make reservations. If you're really flexible, and you don't mind doing things like going to out-of-the-way restaurants, choosing late dinners or early lunches, or eating in bars and lounges that serve the full restaurant menu, you might have more luck. If you're not going to be on the dining plan, you could also try restaurants that don't accept it (more are at Swan/Dolphin or Downtown Disney).