I would go ahead and get a 2 bedroom if it's available. At BLT, they usually have a king in one bedroom, 2 queens in the other, and a pull out queen sleeper sofa and a sleeper chair. It sleeps 9. That way, you're guaranteed to be together since 2 one bedrooms can be requested adjoining, but it's not guaranteed.
For September, the best discount available for the friends and family discount is 40%. more than likely, they will release a 50% discount plus the ability to add either a quick service or plus dining plan closer to September.