We held a friend reunion here with 8 adults and 8 children. Between the guest house and the main house, there was plenty of room. I would not factor in the bunkhouse for occupancy as it was not a place we would have used, but there are PLENTY of pull out couches throughout the houses.
The yard/beach access with children, hands down was perfect and needed. We were able to swim, kayak, and the land itself suitable for obstacle courses, soccer games, and a plethora of outdoor activities. It was about 25 minutes to bar Harbor and Southwest Harbor; a little longer to some of the hikes and bass harbor, bot doable. I HIGHLY recommend this place for large groups. The bonus, no trying to park at Sand Beach in Acadia because they have their own swimable beach. Worth every penny.
Additionally, the owners were friendly, amenable, and responded quickly to emails.