We adjusted the height of a crib and used it as a sidecar when dd#2 was born.
We now have 5 in our family, and have been known to all squeeze into a queen-size bed. (Our older two dds climb in at the foot in the middle of the night. We don't even notice until morning.) I would highly recommend that king size...
Other scenarios while our living situation changed/during travel:
Queen bed against the wall. DP on the outside, then babe, then me, and toddler dd on the side against the wall.
Two twin mattresses scooted together on a carpeted floor/rug, and covered in a fitted King-sized sheet. We've tried this on a hardwood floor: the mattresses slide apart, and somehow I wind up being the person who gets wedged in there every time.'
