Officially, no. But if you call and speak directly to the reservations manager at a given hotel you'd probably get some kind of break. Esp. if you are a Gold or Diamond.
You should also look into suites. Many times they aren't even listed online, but hotels can/will sell them directly if you call.
Sometimes they are <=50% more than a standard room. Then you could all still be together in a large, comfortable living space. But this all depends on the hotel.