Size...as the saying goes...
does matter 
At one time we had a german shepard, a mutt (beagle size), and two cats. Hubby, I and all those animals slept in a
DOUBLE size bed
The biggest bed hog was Penny, the shepard. Penny didn't curl up in a small ball....no sir-ree stretched out full length...which when extended was MY height of 5'. Hubby sat up one night and said...."this bed isn't big enough for
everyone...
someone's gotta go". Told him...."hmmm, here's your pillow you know where the couch is"
Btw, the family that sleeps together, stays together
Another Awww + story, FE