To address the OP...
We have a RE layout currently and only have one child. Sometimes he falls asleep with us, sometimes he falls asleep on the dinette.
I usually stay up around the fire with friends/family until late at night, so it's not uncommon for me to sleep on the couch, while my son and wife sleep in the bed.
We are not having any more children, but our next trailer will be a bunkhouse with a separate bunk room. My son has a couple of cousins close in age and they will likely be going with us, as well as his friends.
With that said, we probably won't get a bunkhouse until he is at least six or seven. We have slept seven in our current RE rig (four adults and three children) and had no problems.
