I have a 20 degree EE Enigma quilt that is great for warmer weather but was thinking about getting a synthetic to layer with it for colder weather. If I want to take it down to around -5 how much climashield would it take? The coldest I have been in here in az has been 3 degrees but that was with an elk hunter bag in a wall tent. If I were to backpack in in similar conditions I could wear my puffy in the quilts but I am thinking I would need a substantial synthetic quilt to go on top. Anyone doing this that can offer insight? Thanks for any replies.