Sierra Designs - Get Down 20 Sleeping Bag

I use this one and it’s light and compact to me. It’s a 20 degree, but they also make a 35. https://sierradesigns.com/get-down-20/

I had exactly the same, in my 50s and I get cold in the night. Try to find a sleeping bag esp for women. They’re warmer. Maybe a temperature rating of -5ish. I got a Sierra Designs Get Down womens sleeping bag. Even though I used it in August in the Lake District it got cold but I was v comfortable. Also a sleeping pad with a warmer R value (warmth rating) helps very much, as it stops the coldness of ground from cooling you down too much. I actually had a winter rated one and it worked really well. Try out also wearing while sleeping something warm like baselayers, a puffy jacket, a pair of down booties from Amazon. 

I have it, got it for $85 from Campsaver. It's definitely not as warm as its ISO ratings, the material doesn't feel as nice as other SD bags, and the half zip is kind of annoying especially if you plan to use it in warmer weather and want to lay it like a quilt. All that said I'm glad I got it as it's rather light for the temps I do plan to use it for. I've taken it out in temps down to the mid 40s and while I wasn't cold I could tell it wouldn't be able to handle much more than that. I'd call it realistically 42F comfort 32F limit, not the 36F-26F claimed. You can tell when you compare the fill weight, 12oz of 550 FP down, to something like the Kelty Cosmic Down 20 which has 16oz of 550 FP down. They have similar ISO ratings but the Kelty has significantly more down, so something must be off. All that being said, it's a decent bag for a 42F comfort rating. It's reasonably light, and can be gotten for pretty cheap. edit: I saw your other post, if you're looking for a versatile bag, this isn't it, this is a warm-ish weather bag. A better choice would be the Kelty Cosmic Ultra 20 which you can get for ~$130. https://www.kaviso.com/collections/sleeping-bags/products/kelty-cosmic-ultra-20-degree-sleeping-bag

I have a sierra designs that is a 17deg bag

Sierra Designs has or had one recently. I tried it out but didn't like it much and ended up going with a Zenbivy which is exactly what I hoped it would be.

I also got an EE quilt and have thoughts on rating - I opted for a 0° bag but this was motivated by spending some uncomfortable nights right around 35° in my Sierra Designs down bag that was rated at that. With a quilt the zero seems overkill but the design has meant I've been comfortable in much warmer temps despite being a warm sleeper generally. I can open it up, hang a leg or arm out, or be just partially covered. They key with the quilt style is having a pad that is matched for the temps you're in. On my last trip i still took my Sierra Designs bag as it packs slightly smaller than my ee quilt but this setup works for me to cover a wide range of temps. Admittedly I missed the mobility of the quilt compared to the mummy but I've spent most of the last 30 years in mummy bags so it's not unfamiliar.

I have a Sierra Designs sleeping bag that has an actual foot flap that allows you to have your feet out of the bag while your body is still in the bag. It’s great. Highly recommend.