Kayu 15 Down Mummy Sleeping Bag -9ºC Women's

Just got back from Algonquin where the temps dropped to 3 degrees C. I was comfy in my fairly new -9 degree C Nemo down bag wearing long base layers only, but I felt if it got below freezing I would need some additional layers. Other commenters are giving good advice when they say a good sleeping pad makes a big difference, especially if the ground is already cold (not just air temps dropping at night). Don't trust temp ratings of cheap bags and aim for something with a rating 15 degrees below the coldest you could expect it to possibly get.

I can vouch for Nemo Equipment bags (I have 3 down ones and one synthetic for different temperature ranges). I can also vouch for Marmot down coats (for in-town use not for winter backpacking or camping) but I have never used a Marmot sleeping bag. My 3-season backpacking bag is a Nemo down 15F version that is probably 10 years old now and it is great except for in extreme heat and extreme cold at night. I have an old Eddie Bauer Flying Squirrel Sleeping Bag (modified with velcro) that I use for extreme heat and other Nemo down sleeping bags for winter backpacking. Nemo has a lifetime warranty on their equipment.

I like the Nemo sleeping bags that have the gills. You can open them when it's warmer and zip them up as the temperature drops. Works much better for me than just opening the side zipper, which I find let's too much heat out.

This. I hate mummy bags. I move too much in my sleep. My Nemo takes up a bit more space in my pack but it is so comfortable and a good night’s sleep, where I can fully roll around in my bag, is worth it. I will never go back to a mummy bag.

It might depend on how you're built, but I can get my leg up like that inside my Nemo bag. I have short legs, though.

I really wanted to love the Nemo, but if OP is a smaller person, Id warn they have too much dead space.

Nemo. Best sleeping bag I have used. On my second one.