HI. I just had to deal with this sitation with one of my guests. AAA policy is the same if you are not within that 45 day mark - no fees, full refund. If you are within that 45 day mark then the fees kick in. They do not like to loose their reservations. Just be sure that you know when that 45 day mark is. If you make your reservation with AAA, mark that day in red on your calendar. Make any changes before then and you should be fine.
Disney usually beats the AAA special at some point with their own promotions. The trick is if the Disney specials come out for the dates you need. The AAA packages are pretty good.