I'd look into the suites. For pricing, you generally need to call to ask about them!
Not sure when teacher rates come out.
The Dolphin has rooms with two double beds, and you can get a rollaway. My friend did this when we went together once (she was in a room with her 4 boys, and I was in a room nearby just with my 2 kids). Her room was quite full, but they were only there to sleep. Comfort to some is relative - it would have been a bit cramped to me, but she took the rollaway and the boys slept fine (ages were 6 - 9, yes she had 2 kids 2 years apart then a year later twins).
Not sure if the suites are offered with teacher discounts, but they sometimes have a special with a second connecting room at a deep discount for families.