Cosmic Ultra 20

If you can wait a bit, like November - May, you'll likely find *much* better value for money from end of season sales. If it were me and I had to buy something now for that temp range I'd probably get the Women's Kelty Cosmic Ultra 20 from steep and cheap for $150. If you're not a woman don't worry, women's just means it has more room at the hips and a bit more insulation. The Ultra version of the Kelty Cosmic has 800 FP down compared to the 550 FP for the regular version, that means it packs down more and is a bit lighter. If you sleep colder consider the Sierra Designs Mobile Mummy 15 from Kaviso for $150. This is the bag I use in the winter and I love it, IMO it sleeps a good bit warmer than it's comfort rating and the ability to use your arms or walk around without getting out of the sleeping bag is incredible for cold weather camping. Here's a video of a guy testing this bag out in 23 deg weather. https://www.youtube.com/watch?v=_-EMsTBMVKg

If you can fit into a women's size bag consider the Cosmic Ultra, it's basically the same thing as the regular cosmic down but with better quality down. https://a.co/d/01ERuBBU If you actually need a 15 degree (limit) bag I can't recommend the Mobile Mummy 15 enough. I love this bag. It's currently out of stock but it comes and goes from this website. https://www.kaviso.com/products/sierra-designs-mobile-mummy-15-degree?variant=45495009935588

You're not gonna touch a decent sleeping bag for under $70. Heck, the Kelty Cosmic Ultra 20 is considered a step above budget, it has an ISO Comfort rating of 31f, weighs 2lb2oz but cost $140-$150 You need to reset your expectations.

I bought 2 sleeping bags this year. I'm just not a quilt person. However my summer bag (37°), bought a Chinese brand Qezer on Amazon under $100. My winter down bag Kelty Ultra Cosmic 20 also on Amazon for under $160. Now I'm not suggesting these are the best or necessarily for you, but I'm satisfied with both of them and don't feel that they broke the bank. However, they are both made of down, significantly lighter than synthetic, and pack down to a reasonable size for my pack.

Well I don't have experience with the katabatic and haven't touched one. But I did research them and the strap system was the selling point for me along with the cost all other things comparable. I feel like the quality is great. Like I said zero buyers remorse. I was coming from a Kelty Cosmic Ultra 20 mummy bag which I felt underperformed this winter. I shaved almost a pound of gear weight and at 30 degrees F (the coldest I've had the waratah out in so far) I was much warmer than I've experienced being in the Kelty, which I would have had to pair with a fleece liner at that temperature.

You're likely to get all kinds of different advice, but the Kelty is a solid budget bag I think. They also have a Kelty Ultra Cosmic 20 that is 800 fill down and it packs down smaller than the regular Cosmic 20, and it's also under $200.

I have the single version of this and also love it. Super versatile temp-wise.

Gnarly! Sounds like some top tier "type B" fun. Early on in backpacking, after several uncomfortable, borderline worrisome nights sleep in my 20°f Kelty bag I learned the advertised temperature ratings of sleeping bags are actually the "survival rating,", meaning you won't lose any appendages to the elements. The comfort rating is always significantly warmer than the survival rating and you often have to research equipment in advance to find thst figure. I'm PNW-based, and personally, fall-winter I use a rei magma down 15 bag & neoair xtherm pad. I might not ook like Jeremiah Johnson all bundled up but I sleep like a baby. Risking death chasing the bushcraft aesthetic in a cold, damp environment isn't worth it if you lack the ability or materials to craft an adequate sleep system.

I froze my ass off with the Kelty Cosmic in 2024

I picked up a Kelty cosmic down a number of years ago. Fairly basic but it was down and a decent weight.