We added a day at the beginning of our trip to a free dining package. We have tickets with that package enough for both stays, and are planning on being in the parks on the first day (POP). We did this last year with an off site first night and just went to customer service at the parks to enable tickets, but is there a way the tickets can be linked to our first night stay? I assume we have to check in to our longer stay (6 nights CSR) for our dining to be activated?
In order to do this you'd likely have to rebook everything. The dining package cannot be started early but you can have your tickets activated early.