Glad to know that you and the family actually make the trip up there to enjoy it.
When we remodeled, I got talked into a small second floor deck. It added cost, but was built well and has lasted trouble free so far. Does it get used? Never.
There's a Victorian cupola with little deck underneath at the family summer place near New Bedford. The leaks are held at bay for the time being, maybe rotting merrily where we can't see it. Years ago, someone had fashioned a little gutter in the bedroom underneath to catch the leaks and channel them back out through the wall. Good old Yankee ingenuity.