bibler hooped bivy sack
Worked well in bighorn mts, wyoming. Positive: Very light, made solo infinitely better. No setup. Packs smaller than my sleeping bag. Kept me completely out of wind/snow/frost. Negative: I'm 6' even, wishing I got the extra-long, as putting clothes/raingear/camera in sack with me for the night made it pretty crowded. Some condensation on the interior floor after nights of 10-20 degrees fahrenheit, but easily wiped dry. Overall: definitely worth it.