I have a modified HH and this summer bought a used HH "underpad," thinking I might have occasion to use it some day in cold weather. But I didn't have an "undershield." (I hope I have the correct terms!)
Anyway, yesterday I remembered I had made an extra-long blaze orange pack cover some years ago, which I let a friend use this weekend. And I got to thinking about multi-function gear. One thing led to another, and I set up my HH in the yard, figured out how to attach the underpad. And then fiddle around with attaching my pack cover. It seems to work!
If I can attach the photos, I will. I'd love to have any comments or suggestions before I find myself freezing in the woods on some hike.