I'm a cold sleeper and I know that I won't do much camping in deep cold, so I went with a 20° full length with overstuff and draft collars. It it truthfully too much in the summer, and maybe I'll use that excuse to diy a down 40° UQ for summer. Then I'll be able to layer the 40 and 20 if I do get into some deep cold. IMHO a 20° UQ and TQ and a very versatile piece of kit, that doesn't have you carrying around way more than you need for most of the year.
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Deep peace of the running wave to you.
Deep peace of the flowing air to you.
Deep peace of the quiet earth to you.
Deep peace of the shining stars to you.
Deep peace without end to you.
adapted from - ancient gaelic runes