Some flukes do exist depending on the flexibility of your schedule. Because some people try to book the mid-week days and not weekends to save on points, sometimes staying over a weekend opens up a few extra opportunities.
I had booked my stays in January for June and September this year...I typically go 4 times a year - and didn't book a December as I wasn't sure what week I was going to be open - I figured I'd get around to it after another month or so. Unfortunately, I had lots of distractions moving my office and with some family health emergencies, and as I prepare for my September trip to Boardwalk next month, I realized I had never booked a December trip yet. So two days ago, I hopped onto DVC to check if I was out of luck sometime in the first two weeks of December - it looked bleak for a 1-bedroom for Fri - Tues, 1st - 5th. Tried 8th - 12th and there were spotty rooms, but none fully available. But when I checked the available days chart, I noticed that the initial Friday the 8th was the one not available - at Saratoga or OKW, I could get all the other days, and Wednesdays were open too. By shifting my reservation to Saturday the 9th through Wednesday the 13th, I was able to grab a Preferred 1-bedroom for this December, at less than 3 months out.
This would be more difficult for a family planning a big Disney trip from out of state, arranging planes and times off - I'm a Florida resident, an easy 2 1/2 hr drive away, often just travel with one family member or friend or sometimes solo, and I have plenty of vacation days at work so I can easily shift the trip by a day or two as needed. And if you were looking for more than 5 days, that would get significantly more difficult at this short notice.