In my experience there is a learning curve with a quilt. The first time I used one in cold weather, I got really cold due to drafts and not wearing anything on my head. Were I in your shoes, I would start using a quilt in warmer weather and then work towards using one in colder weather as I gained experience. Using a 20°F quilt at 0°F could easily make for a miserable night.
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May I walk in beauty.