I just called to ask about this. It’s a 30 day window for everyone regardless of existing reservations. Once you renew, you are then able to make reservations for the dates on your new pass, but you have to wait until the 30 day window and hope that they still have renewals available as well as park reservations. It’s unfortunate timing for us since our passes expire in the middle of our VGC trip, and it’s not like we can even move that because VGC is fully booked.
We are in a similar situation… we have the week before New Year’s booked at VGC and now we’ll need to buy tickets. We’re still going because our vacations are scheduled around school, but I need to calculate whether it’s worth it to still buy MKs and pay over $2K each for “Dream Key” level coverage, or just reduce our trips and buy tickets instead.