You can ask when you check in for your reservation, but there are no guarantees. In fact La Hacienda is a restaurant where others have posted that often the hostess at the podium said they were not taking requests so you would have to take the next available table for your party size. Also, if you are going when IllumiNations is at 9 PM it will be even more difficult since most who have a window table with a good view will stay until after the fireworks.