Marmot - Women's Phase 20 Degree Sleeping Bag

S2S seem to have 170cm options as well. I have Marmot Phase 20 wmns bag and love it, it is warm and have been warm in - 19C with it with merino base layer but I guess it depends on a person.

I'm similar to OP in terms of height, weight and can sleep cold. I got a Marmot Phase 20 on a really good sale (40% off) about 4 years ago. (20 as in 20F which -6.7C). It's great around 0.0C and I've taken it comfortably to -5C or colder, but wearing a lot of down and such with a very warm pad. I'm not American, but the Fahrenheit ratings that come in multiples of 10 are kind of handy - get the one "10" lower that your general expected use because the nominal ratings are not necessarily comfort ratings for you and things will get colder from time to time.

Marmot phase 20. 23 oz. Better r value pad. Don't cover head and breathe into bag. And that's alot of layers. If you're wearing so many that you're a tight fit in the bag you won't be making a very good pocket of air to keep warm.

Years ago my wife and I got 2 marmot mummy bags. One with a zipper on the left, the other on the right. We still have them and they work great together. Plus they work independently for solo trips

Marmot is a solid brand, like the other commentor said its a personal choice. I would invest in the Marmot down fill bag myself and thats based on the longevity and utility of all my other Marmot purchases.