I have perfected my ultralight, minimalist solution to cold weather hanging. Low cost. Minimal gear. Ultralight weight. No fiddling around with top quilts and bottom quilts. No sleeping pad inside the hammock.
Here is the list
Grand Trunk Nano 7
Whoopies suspension, straps with marlin spike & dead stick used for toggle
Hammock pulled through inside of down bag with zipper in footbox. I use a Kelty Lightyear, which has a little zipper in footbox.
Space blanket mylar turned into a mummy bag shape used as vapor barrier liner inside of sleeping bag. This mylar mummy bag came shaped as the mummy bag with the seams taped up nice and strong.

Here is a link to the mylar mummy vapor barrier. Many sellers sell these on amazon and other sites as emergency sleeping bags. http://www.amazon.com/gp/product/B001MGS67A

The mylar mummy bag vapor barrier weighs 3.9 ounces. In the ultralight world, that's a lot of weight. But, a down bag can gain, on average, a pound of weight per day on the trail from insensible perspiration that gets trapped in it as you sleep, and you can rarely dry a bag out on the trail properly. So the 3.9 ounce weight penalty goes away on the second day of the hike, and turns into a 12 ounce savings. On the third day, you enjoy a 28 ounce weight savings. Fourth day, 44 ounces. This is big weight savings on a multiple day hike. Plus, you sleep warmer -- maybe 10 to 20 degrees according to what you read. Keep the tarp rigged to block wind, and you have a very toasty, inexpensive, ultralight setup without all the fiddling around with top quilts and bottom quilts, etc.

This video shows the hammock-through-back setup, but doesn't show the mylar vapor barrier. http://www.youtube.com/watch?v=4C9hZYe4dno