Many thanks to all who have responded. We have decided we're going to book a 2 bedroom at BCV. If they want to join us, they are more than welcome. If not, then they are welcome to book their own room and join the rest of us when they can. The sad part is they can't afford to stay at BCV and will probably stay at one of the value resorts - which will limit our time together. Especially since they won't be able to access SAB.
Regarding being cramped, I think we'll mainly just be at the resort to sleep and use the pool in the evenings. We'll probably be in the parks from morning till night so I'm not really worried about having enough seating at the kitchen table. I typically eat while getting ready anyways. I think getting ready in the morning's will be the biggest hurdle, but we're early birds whereas the others aren't so we'll probably be ready by the time they wake up to use them.
Joan - I'm hoping your perspective of so many in the room not being too bad is correct. More space would be desirable, but as I mentioned, we want BCV this trip for location, the pool and the whole resort.

We're willing to accept being a little cramped in order to get our desired location. My sister/husband don't mind that either. They figure we'll be in our room so little it won't really matter in the end, plus it's free. Hopefully we just won't all hate each other by the end.
Thanks again everyone!!! Next May can't get here fast enough!!