I've done this two different ways.
I've mostly stayed off site recently. I really like the Holiday Inn Suites. They have a wonderful pool and all their rooms are two bedroom suites. Which means the parents get their own room, with a tv. The kids get their own room, with bunk beds, there's also a tv, and nintendo 64. In the living room, there's a pull out couch, with a tv and vcr. You only have one bathroom, but that's okay. I've been able to get these suites for as low as $89 during the low season or $149 during peak. It's a really great deal, especially when you consider that you get a free breakfast buffet (hot food, with pancakes and bacon, as long as you get there early) and kids eat free in all the restaurants. And for those of us with larger families....It means 1 paying adult per 4 kids!!!
The other thing that I've done when I've had to say on property is book the package as for just me and two of the kids. Then I call CRO and book another room with one of my discounts, usually an annual pass. Then a week or so before I go, I call the resort directly and ask them to make sure that I get connecting rooms for the reservations.
Good luck!!!