I've got a frozen cape off of a 2017 September Utah bull that I am willing to part with. Make me an offer and I'll see if we can come to terms. I can send you field pictures of the bull too.
I use a Ziploc Freezer bag. Just blow it up to desired amount of air, seal it, and wrap it with a shirt or other article of clothing for comfort. It's lightweight for those back-country hikes and adjustable to your liking. Love it!