Kind of a long drive from NYC... but Arcadia National Park in Maine is really nice for biking. There are carriage roads that the Rockefellers made that give a great view of the island. My family did it last summer. Also there are bunch of bike shops.
Funny that you should mention Acadia, Maine is my home state, and I've ridden those roads with my parents many years ago. The Maine coast is highly recommended, but as you say, a bit more of a drive from NYC.
Regarding Burlington, it's worth noting that there is an Amtrak train that runs from NYC to Burlington, it's called the Vermonter. Not sure how the cost compares to renting a car, but you wouldn't have to deal with the steering wheel (and all the cars) being on the wrong side.....
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