Twin - Cubicles, which consist of one bunk-bed and about 3 feet of space between the bunk-bed and the wall. It is too small to do anything but sleep in, and even then it's not much space for 2 people. But you do have privacy.
There is at least 1 cubicle with a double bed instead of bunk beds.
Group - Family rooms, which are more spacious with 2-4 bunk-beds. If you wanted a family room, there would be other people assigned to it as well. Last year a number of Mountain Medley participants who didn't know each other were assigned together in family rooms and it worked out well.
There are 5, 8, 10 and 12 person family rooms.
Dorms. The dorm rooms are separated by room dividers that don't reach the ceiling, so although you have a little privacy (there are 4 or 5 beds per room), there is no way to mitigate noise. However people try to be considerate and if you are a good sleeper you should do fine in a dorm room.
You can certainly arrange to sleep in the same room with your traveling companions, but there is no way to pick additional roommates. The Lodge assigns them.
Beds have pillows and pillow cases but you need your own sheets and blanket or sleeping bags.
The average low in August is 37° and the 10-year low day was 28°.
There are no heaters in the rooms.
There are no private or semi-private bathrooms.