sleep system

Hi everyone, if you could tell me what you have for your sleep system for one overnighter light mountaineering in summer/fall?  All my gear is >15 years old and bulky and from what I'm reading people are doing overnighters using 30-40L packs and I take having a small pack like this is just part of your entire 'fast and light' system.  Everything inside it must be taken into consideration.

When I mean overnighter, chances are I'll be setting a basecamp and heading out for some day climbs.

Thanks

I can get a freezing temp down sleeping bag, Thermarest Neoair Xtherm Max and a bivy bag in a 50L pack and then I still have room for other gear. That sleeping system would fill my 40L packs almost to capacity so that would mean making concessions in terms of comfort or strapping lots of stuff on the outside of my pack - concessions you don't really need to make if you're camping in the valley/moraine fields/glaciers.

 If I'd be setting up a base camp I would take a larger pack on the walk in and take a lightweight daypack as an extra for the technical stuff. 

Neoair xlite pad, 20-30* quality down bag (I have a feathered friends bag, would recommend).

Maybe a ground tarp if it’s clear out, or a light tent if expecting weather. 

The ultralight subreddit has good info. I comfortably get away with half of my 35l bag taken up by the essentials.

Neoair xlite and an enlightened equipment 20 deg quilt. Weighs a combined 2lbs and takes up maybe 10-15L, and since you'll pack the quilt loose instead of stuffed, it really utilizes every inch of space. Ive done almost 2k miles with this and as long as the low doesn't dip below 20 you're fine.

Neoair Uberlite

Feathered Friends Vireo sleeping bag (the one without a hood or a zipper)

Down filled puffy jacket

This is my go-to 3 season sleep system.  

For colder conditions or sleeping on snow, I substitute a Neoair XTherm for the Uberlite.  

If you're doing something where you are already bringing a "belay parka" type jacket then consider either an elephant foot type bag or buy a used childrens 20-30 degree sleeping bag (cheap and very efficient, considering most childrens bags don't get nearly as much use), and sleep in the parka as well. No need to carry all the extra loft if you already have a do it all warm puffy, especially if you are not open bivying. You can get away with a warmer/loftier synthetic bag as well if its a childrens size, which is necessary for wetter climates or multi-night adventures.Carry a 3/4 length pad, use your pack to insulate whatever end is still sticking out. Use the extra room to carry more fuel for filling a hot water bottle and a spare stick of butter for those chilly nights. 

Thanks for replies.  Any experience with sea to summit pads.  Person at store says its more comfortable.

They're well regarded. 

Really depends on how comfortable you want to be, precipitation and bugs. If it’s a climbing trip with a little sleeping, I sleep in my cloths and down jacket with a 20 degree ultralight down bag, zrest 3/4 length pad and an ultralight ground cloth/tarp which can double as a minimal shelter if there is unexpected rain. In total this adds about 2.5 extra pounds, is fairly comfortable if you pick your campsite well, and you get to look at the stars at night. If there is rain or bugs I use some or all of a UL tent. I like the foam over an air pad since it will not deflate and is quiet. Also doubles as a good camp seat.

I just want to plug Nemo bags. I love the spoon shape, although it isn’t the lightest design (more material), I feel like I have restless leg syndrome in a mummy bag.   They also have vents that you can open to regulate the temperature so you can use them in much warmer temps.
I also like Big Agnes bags with the pad sleeve/no fill on the bottom. 

For perspective, another option to at least explore If you are just talking 1 night in summer/early fall  alpine, I recommend experimenting with skipping any tent, sleeping bag, bivy sack, etc and just go with a fist sized SOL bag and neo air or even space blanket type bag and maybe a super silky and lightweight tarp over you if any chance of precip.  Try and keep your whole 1 nighter kit to the size of a Nalgene bottle or less.   I typically find it works great....by the time I’m just getting miserable, it’s also time to roust and get going, lol.   Nothing hampers/delays a day’s objective more than a warm, comfy sleeping set up!  You actually get more net enjoyment this way as well...just on the longer hike up and down, rather than during use 

Experiment on your deck at home to get your temp range and system dialed and confirmed before trying in the field.  

I love my Nemo bag for comfort, but it is big and bulky(mine is an older model and the newer ones have a more trim design that is lighter and less bulky) I can also vouch for their z-fold foam pad, I like it more than the thrrmarest, warmer and softer for 1oz. I did a single night with climbing gear in my 35l. My helmet and pad were the only things strapped to the outside of my pack. We had a good forecast so we skipped the tent and ground cloth, we were also doing a single night so we did no cook food so that saved on storage as well.

That said I have been looking at getting a lighter and smaller setup, I have been looking at the klymit xpad, and a quilt, probably the enlighten quilt or make my own. I use an alcohol stove but I have been eyeing a solid fuel stove, i only ever boil water so why carry the heavy stove and fuel cylinders.

Making those switches I expect that I could add my 4 man pyramid tent, cook kit and food for another day or two.