The policy the last several years is each adult in the current reservation can book 1 room. You can book multiple trips per adult for different dates, but just 1 room per adult per trip. Then that adult has to stay the lead on the reservation. So you'd have to list families in different rooms. Then you can sleep in the right rooms, but it can get complicated to keep track of whose credits are whose.
There was a report last week from someone who said she was allowed to book 3 rooms. But that seemed to be an isolated incident.