Light Quilt Convertible 25° Down / Large

+1 on ZB. I have their 25-deg light quilt and sheet. Never slept so well hiking.

You can get a 950 FP Zenvbivy UL 25 degree quilt that is right at 1 lb. I'm not saying there aren't others lighter as I'm sure someone is making them, but it's incredibly competitive. Add the uninsulated fast sheet (3 oz) and you're at 19 oz. or get an insulated one that adds under 6 oz. (probably not needed by the OP based on her expected use but not a bad idea) for a total of under 22 oz. Again, someone is doing it lighter, sure, but barely, and without the comfort the sheet provides. I looked around at various options yesterday and 19 oz. is incredibly competitive for a 25 degree quilt and the ZenBivy even compares okay in price. If you can wait for one of their sales, it's not uncommon for them to slash 25% off of everything on their site.

Sure, like I said. It's competitive (within 5 degrees of "comfort limit") even with the sheet. I've taken my 25 degree Zenbivy down to 22 degrees recently and it was plenty comfortable, BTW. That's anecdotal for sure but it is what it is and I know I can trust mine down to that temp. I'm sure the Katabatic is great, no shade. Just noting that the best ZenBivy is competitive for the weight, especially when that weight includes the sheet.

Although I think this is true, I also think the actual lived experience of my 25 degree Zenbivy indicates that the rating is fair and I am pretty sure the sheet system helps with that (eliminating drafts plus the warmth of the hood). I have gotten my 25 degree Zenbivy down to 22 and was plenty comfortable. Fill is certainly important but it's not the only metric.

Something to consider is Zenbivy's UL 25° degree quilts are under filled when compared to other manufactures for similar limit rating range and may be colder as a result (*however, individual results may vary*). The UL 10° degree quilts are more on par regarding fill weight with other brands and IMO more consistent with the comfort/limit rating than the 25° degree quilt. Good luck.

Note that that 25 degree rating is the *limit* rating. The comfort rating is 35 degrees. For reference, at 19 ounces you could get a katabatic quilt comfort rated to 30 degrees.

35 degree down alps mountaineering quilt. 1.5 pounds. Maybe the best piece of equipment that company has ever made. Or a zenbivy 25 down same weight. Depends on how windy, how much other clothes a I want to wear. Get off the ground if you can with a cot- car camping. Way warmer as the ground is 10x denser than air and sucks the warmth into the ground. A cot also offers better ventilation and you will have to practice venting vs cold.  At some point it will be too cold for you in a 3 season tent and go with a warmer sleep system-   insulated mat with a good r value, wool liner, light wool gloves and balaclava, 0 bag, new tent. Hot water bottle wrapped in your thickest sock stuffed in your bag! Like the folks say here- new dry clothes on a dry body in a dry tent. I've slept in cold on purpose and some really horrible mistakes have been made. 41 is entering the cold zone. 

I have a ZenBivy "Light". It's quite comfortable and does work as designed. But the extra stuff adds a little extra weight. Maybe worth it in cold windy weather. Not worth the weight in warm weather. They do now offer an "ultralight" quilt which I have not tried. If I were to buy a quilt again today, I'd probably try an Enlightened Equipment custom. If the ZenBivy idea sounds really good to you then consider it. For ultralight, you should consider the weight. You don't need to user their pads (I don't). Just order the sheet size that fits your pad size.

I have a feathered friends flicker 30 degree and lark 10 degree. Those cover all my bases. I do have a zen bivy 25 which is nice but heavier.