We just went there on Jan 15th, and my advice is GO EARLY!!!! And you can probably sit anywhere you want.
We had reservations for 5, but left DHS early to make sure we got there in time, and arrived at 4:30. There was no one there, seriously. The bar was empty, there was one other table of people where we were in the fern room. Our waiter was very attentive.
At 5:30 when we left, there was a line from the podium inside out to the sidewalk, and every table was full.
The fern room was nice. The ice room was very pretty, but can't imagine trying to eat in there with the blue and pink lights. If we ever go again (many years hence) I think I'd like the aquarium room. Then we can skip Coral Reef!