This is a possibiliity but requires a member who is not afraid of a challenge.
Under the new system your reservation(s) can be made in multiple segments. So, a few days could be with a certain number of people followed by a few days with a different number of people or with or without dining plan, or any split in between. Each segment will have its own reservation number but will now include a travel plan number. This travel plan number is key to making sure the reservation is one long continuous stay, so no room changes are required.
Keep in mind that this is very new to Member Services and very new to the resort check in people so there are bound to be misunderstandings along the line.
David