Here's my one and only post on the pool rehab and my PERSONAL FEELINGS on the subject ... again ... this is only MY personal opinion ... everybody has different feelings on the subject!!!
In the past, the pool maintenance is done in the winter months almost every year. It has to be done obviously ... just like Typhoon Lagoon and Blizzard Beach ... it's 3 acres ... it takes more than a day to do yearly routine pool maintenance. Naturally they do it when the weather is normally so cold that most people do not want to use the pool. In the past, they also have done it in three sections so all the time, at least two-thirds of SAB was open ... not that there is a lot of people in the pool when normal temps are in the 50's and 60's. When the slide portion of SAB is down, they have always taken people that want to slide on a pool slide over to the Boardwalk. They had a continuous cart driving people to and from during normal pool hours ... again ... with the weather normally not "pool" weather, the carts were normally empty.
All three other regular pools (BC, BCV and YC) were always open during the SAB maintenance in the past years as far as I can remember.
In the past, we all found that if you booked through a
travel agent or through Orbitz or some way other than directly thru Disney, you will probably
not receive the standard letter that is sent to all reservations that are booked for the period during SAB rehab. Those letters go to the travel agent or Orbitz or whoever booked the reservation ... whether or not they (travel agent, etc.) forward it to you is out of Disney's control. If you booked thru Disney, you should receive a letter saying a portion of SAB will be under rehab while you are there ... at least that is what we all on this thread have found out happened in the past.
In my personal opinion, if the pool rehab will ruin your stay, I personally would change my reservation to another resort. And I personally would definitely do that during the months of April thru October. However, any time I go to WDW in the winter months, I don't even take a bathing suit. But that's just me. But you spend lots of money on your vacation so if you are going in the winter months and swimming in a big pool with a great slide is a huge factor in your vacation, then you should move to one of the other Disney resorts that would suit your needs more. If you think you will just be using the pool for 30 minutes or so every day (mainly because of the weather), then I personally would not change resorts. There are other pools there and only one-third of SAB will be down during your stay so you can definitely use a pool at Y&B.