We are going in early may and just planning two MK days only. If you bought your tickets already, you can book your FP+ at the 30 day mark at midnight. There will be availability for most but probably not A&E or 7DMT. My advice for one day is to get there prior to rope drop and take advantage of the short lines at that time. I think you probably can book a character dinner at Crystal Palace but times may not be ideal, CRT is likely all gone. If you are just going to do one character meal I would go with Tusker House on your AK day. FOllow the cancel board for May to see what other people are dropping and you may get lucky! Plus, i find that lots of people cancel the day before, so dont worry too much if you cant get anything, it will probably open up eventually if you are on top of it. Or pay $8 for one of those notification systems like Disney DIning BUddy, and let them search for you. GOod luck!