Thanks so much for the helpful replies! I had no idea re the 499 booking window. Looks like Molly the Shih Tzu will have to go to the kennel this tome.
Yes, our DD is running in the Princess Half Marathon and we're going to cheer her on. We decided to book at Pop ($170/night!) this time. We never travel to WDW during the busier times so this has been a learning experience!
Thanks, again!