Anonymous wrote:It's one big house, so perhaps not exactly what you want, but my family stayed here this past summer with a big group like yours and it was spectacular:
https://www.vrbo.com/340408
We had my family of five, my sister's family of four, and my brother and his wife in the main house; my parents in the 70s stayed in the "carriage house" also on the property (connected by a breezeway to the main house. Like yours, the kids in our family ranged from ages 6 to 12. The house was big enough that there were many wonderful rooms and nooks and crannies (and, outside, separate areas of benches or chairs or tables, walking paths and a veggie garden) to explore and we never felt that we were all on top of each other.
We had been to Boothbay Harbor a number of times before so we knew it was a great place for kids-- hiking, kayaking (this house has kayaks and its own dock), boat trips, aquarium, shopping, etc. I highly recommend it. And it's only an hour north of Portland, so it's so much more accessible than Mt. Desert Island (which is also gorgeous, but a bigger hassle to get to).