It's kind of a mess right now. You shouldn't have to pay anything at the moment... it's all credit card reserved, but not payment up front. It seems you can book Minnie's Holiday Dine with Fantasmic online and by phone. Minnie's Holiday Dine with NO Fantasmic, is not available anywhere. But... you can book a dinner at Hollywood and Vine with no mention of Minnie's Holiday on the phone, and using the My Disney Experience app, but not using a browser on your computer. But I'm not sure how they could offer holiday characters and food on one side of the room and not the other.
With Fantasmic Holiday Dine's.. are going fast. Dinner at Hollywood and Vine with no mention of Minnie's Holiday, are still available. I've booked one of each just to be sure, and will cancel the one that's missing the holiday cheer... or the more expensive one, if there's holiday cheer at both. I can't imagine this was the plan... but everyone is in the same boat... my guess is there will be much booking and canceling and booking and canceling.
(I'd like to make a reservation for the Food and Wine Premium Package... what's included with that? Sorry... inside joke.)