Park Reservations with Resort & Ticket Package ???

[DisneyCowgirl]

I have a stay coming up on a package. When I initially made my park reservations, it had me somehow go through my hotel reservation and it appeared I had a different availability pool I was drawing from. Now I would like to change one of my days from DL to DCA, but it won't let me see availability as all days of my ticket are already booked--I have to cancel a reservation before I can see availability. I don't want to do that and then find out there is none and I've lost what I already had.

I can see where you can see the calendars if you have a ticket or an AP. Is there somewhere I can see availability for resort packages? Or am I wrong this is a separate pool of availability?

For reference, we are going the week of March 13th and some of those days are booked up for regular ticket holders.

Thanks in advance!