So, this has been my biggest frustration. We are out of state WDW AP and DVC.
We generally do one week long trip in the summer, and stay at DVC. No issue there. You cam make reservations
The rest of the time, we tend to do long weekend trips, where we stay off-site, and often at a hotel I have some points or free nights.
As a WDW AP, you can reserve up to three days at a time.
We did a trip (I believe it was Labor Day weekend, where we planned to go to the parks for 4 days. We could only reserve 3. After the first day, there were no reservations available for any park on our fourth day. After the second day, still with nothing available, we decided to cut our vacation short. Canceled the last night at the hotel, and returned home after we spent our three days in the parks.
You cannot plan longer than a three day trip if you are staying off-site. That is frustrating as we have a few four and five day weekends where our kids are off from school that we cannot take full advantage of.
I keep hoping Disney will stop the reservation requirement, like basically every other amusement park company in the US has done. I believe Six Flags stopped in May, Cedar Fair stopped most parks in June, with a few lingering for a couple of weeks. Seaworld Parks and Entertainment (including Busch Gardens) stopped in July.