G4Free Hammock Underquilt for Single & Double Camping Hammocks, Lightweight Portable Top Warm 4 Season Winter Under Quilt for Outdoor Camping Hiking Backpacking

I was eyeing the OneTigris one, ended up getting this very similar one. Put a 25⁰F bag inside it and was warm as low as 35⁰. Tried it later down to 40⁰ with an un-rated camp blanket instead of the sleeping bag and was fine with that too. Could easily have gone at least 5-10⁰ lower with either system, both were very toasty. Mid-October in NY will be chilly at night though, definitely colder than the late-September times I'm referencing. I'd consider bringing the self inflating mattress and camp blanket if you do get the cheaper underquilt and the extra weight isn't a problem, or testing the system at comparable temperature closer to home before taking it into the wilderness at least.

I have this one, it's cheaper than just about any alternative and is dead simple to set up. Very warm too, you'd only need to replace it if you need less bulk or weight in the future if you stick with hammock camping. I also considered trying to rig something I had for the first trip, but this was so cheap it felt silly not to do it right. Paired it with an even cheaper hammock and tarp setup and regular sleeping bag, and had a great time. Considered this as an even cheaper option, saw a few positive reviews on here about it.