I think the reason we can't get the Grande Denali from them is because HAL and RSSC have the rooms on reserve. Right now, we don't have the minimum to run the trip as it is, so I don't feel we can protest anything.
Editing to add: I called and spoke to them. We only have a minimum to have our own bus. We might be able to tag along with a Princess or HAL group and we can get what they call a guaranteed departure. They are going to send me more info.
