We had 7 in a dedicated 2 bedroom (3 adults and 4 kids), and we were tight. DH and I had the master, Dh's sister and her 2 kids had the 2nd bedroom, and our 2 boys slept in the den.
Our boys in the den really had no place to "escape" to for a little peace and quiet from the other kids. Their sleeping space was also the living space, and after a few days, they needed some separation.
Is there enough sleeping space for 8? Yes. Is there enough living space for 8? Not for our family.