The cost is $186.38 (including tax) for the dinner only. You can book at 180 days, and with my resort reservation they honored my +10 (which worked out well for me because I was looking to book on the last night of our 10 night stay.)
There is a 72 hour cancellation policy, and there was only one seating. (Ours is at 5pm)
I can't tell you much more about it, but I will know more about it when we get back in February.