I have general advice. I used to visit a retreat center each year near the base of the Poconos that is exactly as you describe. My memory is not super clear, but I recall enough to want to book a trip even now. To arrive, I'd fly into EWR, PHL, or ideally ABE, but that was always the most expensive. So I would rent a car. That's the variable here. I'm sure you're sane, so you don't want to drive in NYC; however, if you don't hate the idea of getting toward EWR and renting a car or even taking a bus or something else, I'd suggest heading toward the regions northwest of Allentown/Bethlehem/Easton, PA. For me, it was a 2 hour drive to the retreats I attended. They were at a campground--modern cabins, etc. Up there you find charming little places like Orwigsburg in Schuylkill County, Jim Thorpe, and the Blue Mountain area. There are some brand hotels, but there are bed and breakfasts. There are also cabins where you would find precisely what you want. The views. Oh my! I wish I were there now. Yes, a small distance but you do have a decent amount of time. School starts again after Labor Day, so it's likely a good time to go. Weather is anything from hot and sticky to cool and crisp, but probably nice.

Whether you head that way or another, you don't need a flight. And in fact, you might do okay heading to Grand Central Terminal and heading upstate. I've done both, and I'd return to PA in a heartbeat. In fact, this post has me crazing pizza in a tiny Orwigsburg place, which was easily as good as what I had in NYC before heading in. Perhaps someone who lives near or has better experience can offer specifics.

You may need to sleep somewhere in NYC the first night, but trust me, it would be worth it--and fresh air, peaceful, and quiet-filled. You may never leave.