Family trip in Northeast US / Great Lakes / Canada with luxe summer camp / lodge vibes?

Hi! Hoping to consult the travel hive mind here for ideas on destinations for a multigenerational summer family trip (July-ish). We are a group of fourteen spanning three generations - kids aged 5-10, parents 35-45 and grandparents early 70s. 

In years past we’ve rented vacation homes in various locations but none we liked enough to return to and I’m weary on the rental house experience. I’d love to find a lodge or small resort property that fits the bill. An ideal set-up would be somewhere that has small cottages / cabins on the same property, is family-friendly and has dining options and some activities on site.

Many in the group do not like big resorts, crowds, or anything overly fussy or formal. No golfers. The kids will be happy with somewhere to swim like a pool or lake, grass to run around on, and other kids to play with. Parents and grandparents will be happy with comfy lodging, good food, nice scenery and laid-back atmosphere. Good quality food is essential.

Budget: lets say ~$65k for a week for lodging and food, not necessarily firm (though please suggest anything you have in mind regardless of budget, I keep a list for future travels!)

Location constraints: Needs to be within a 2-3 hr direct flight from IAD or DCA… I’m thinking that something in the Northeast / New England area, Great Lakes, parts of Canada would all work. Not really looking to go south due to heat.

I saw Migis Lodge in Maine mentioned on another post and something like that looks pretty great (minus the dinner dress code, but could deal). Are there other places like this that come to mind?  

Thanks!