Yes we have extended trips. We used the Annual Pass discount. If you qualify for any discounts you can use them. You have to call reservations to book. The resorts will offer you rack rate. It definetely not true that you have pay rack rate on a "day of reservation". I have also arrived a day early. I called from the airport and was able to book CSR with a Ap discount. I got to the resort an hour later. I hate when people are given wrong info on these boards.
You were just lucky they still had rooms available under the AP discount promotion. They alot only so many rooms at each resort for each promotion. The first time I stayed at POP Century several years ago I was booked under the AP discount. I walked in, took one look at the screaming kids running through the lobby, and thought no way. When I got to the desk I asked the CM about switching to another resort and she said I could, but I'd be paying rack rate if an AP discount was not available for that resort and that I'd be better off calling CRO myself. I got out of line and called CRO. I was told there were no longer any AP rooms available at CSR, POFQ, or PORS for those particular dates. CBR was the only moderate that still had rooms available under the AP discount or I could use the AP discount at two of the All Stars (forgot which two, but the third didn't have any AP discounted rooms available either). I'm not a fan of CBR, so chose to stay at POP. I could have gotten a room at rack rate at any of them.
Once I did a split stay at AKL and CSR using my AP discount for both. The day before my CSR reservation was to start, I called to see if I could just extend my stay at AKL for the whole week. After checking she said there were no more pool view rooms available at AKL under the AP discount for those days and I'd either have to pay rack rate to keep my pool view or I could upgrade to Concierge level and use the AP discount, as there was neither any standard, pool, or regular savanna view rooms available for the AP discount. I chose to do my split stay and just moved over to CSR like I had originally planned.
In both instances, since I already had rooms booked under the AP discount, I could have moved to another resort and kept my AP discount,
as long as the resort I wanted to move to still had rooms available under the AP discount. Even if the dates had passed for booking under those AP discounts, they said I still could have moved or even added days onto my current reservation. The problem both times was that there were no more rooms alotted for that promotion at the resorts for days I wanted.