In years past my group has crammed up to 8 people in one of those Marriot Downtown rooms. Two in each bed, and two air mattresses with two people each. It was...tight. I don't really recommend it. There is room for two air beds, but they will use up the entire floor so hope no one has to go to the bathroom in the middle of everyone sleeping. We also tipped up the air beds for more space during awake time.
One of our people tried to sleep on the floor of the closet once. That didn't work out so well.
That just sounds miserable.
We've had 2 twin air matresses in these rooms before. Twin size will fit nicely between the queen beds and another one between the window and the bed. As long as you are "friendly" it could sleep 5-6 with people sharing the double beds.
Keep in mind though that this is against fire code as the max occupancy of those rooms is 4.