Timmermade - Wren False Bottom Sleeping Bag – Fetal Position

For the sleeping bag I’d recommend a zpacks, timmermade or cumulus 30f range sleeping bag you could push into much colder temps wearing alpha 120 bottoms, down jacket, and down foot booties inside the sleeping bag. I’ve used this combo of clothing to push my 12oz 50f sleeping quilt down to 20f comfortably. If you plan to camp mostly in the summer I’d get the 50f bag and just wear more clothes inside it to push temps lower in fall. I switched to this technique and was able to reduce my pack size a lot and half the weight of my sleeping bag and its bulk. It works well since I’m already taking the alpha pants and down jacket anyways so I might as well wear them and save weight on the sleeping bag. The wind makes the biggest difference to me for how much insulation I need at night. For High Wind below freezing a windproof bivy that can fit over your pad and quilt makes a huge difference to your overall warmth and stoping drafts. Many UL quilts with 7D fabric are not very windproof and even a 20f bag can feel very cold at 20f in high winds. I like to summit camp and it’s often very windy above 6000ft. For the sleeping pad I’d recommend the thermarest nxt https://cascadedesigns.com/products/neoair-xlite-nxt-sleeping-pad?srsltid=AfmBOop1YJvl8n8oPU1vCNvveJ5sopEYhuUIcb1ORgJmz5-Sc-vxRd-W If 6.1 and the wide thermarest fits me but is still small. It packs down very small and is the most comfortable and insulated pad for the weight that I’ve tried yet. I have slept at 10f in the snow and been fine with it. You can also pair it with a gossamer gear thin light foam pad and gain more R values for freezing temps.

Outside of the Serpentes the timmermade line has been updated in recent years to be a more true comfort rating I believe. You can read about it on the website. I think the Wren is more true to the comfort rating, while still having the false bottom system Edit: I’m realizing you’re talking about venting in warmer weather, and it is a downside but can be worked around if you let parts of your upper body out. You do lose being able to stick a leg out easily though. I believe Dan will make false bottom bags with zippers if you want to though

Checkout the [false bottom sleeping bags](https://timmermade.com/product-category/sleep-systems/down-sleep-systems/) from Timmermade. The differential baffle design and false bottom design is the best warmth to weight ratio bag I have used and seen. It is paired well with a water bear hood. The false bottom of a Serpentes bag reduces the overall weight of the system by approx 10% over an equivalent size without a false bottom, depending on the dimensions and fill quantity. Dan is very helpful and you can customize the fitment and materials.

Fellow rotisserie sleeper here. Mostly camp in my hammock but also go to the ground when I have to, e.g. routes above treeline. I’ve done quilts and mummy bags on the ground, and I don’t like either in their traditional forms. A third viable alternative is what basically amounts to a hoodless “bag” of some sort: a false bottom bag (Timmermade Serpentes/Wren), a zipperless bag (Nunatak Sastrugi), or a fully zippered quilt (Feathered Friends UL Wide Flicker). You have the option to select from a variety of sizes to suit your needs especially with Nunatak and Timmermade, but be aware of the lead times and specific ordering windows that will require some patience and diligence on your part. I find I sleep less interrupted in these types of bags on the ground, while traditional top quilts do just fine in a hammock system with an underquilt.