Does anyone use an Arc Alpinist in winter?

Unless you sleep cold you should be toasty to 10F provide your feet and legs have something over them. I am a moderately warm sleeper. I have been comfortable down to 10F using a ghost blanket, thermawrap jacket, and golite snow cap. All are less warm that you list. Under those items I was wearing mid-weight wool sock, Sahalie ultra-light tight, cloudveil spinner pants, sekri level 1 (featherweight) long sleeve base, polar buff neck gaiter, cloudveil six shadow beenie.

Hi Petras,

You may want to consider the Feathered Friends Vireo Sleeping bag with overfill (mine has 2 oz overfill), Feathered Friends Hyperion Jacket, and Feathered Friends Volant Hood. Order all with 800+ down. If you order the Feathered Friends Vireo and a Feathered Friends Jacket, Feathered Friends will give you a 15% discount on the Vireo and the Jacket. If you get the Hyperion and the sleeping bag, get the Volant hood and have Feathered Friends add the snaps and the fabric for the snaps added to the Jacket and the snaps added to the sleeping bag and the hood. That way you can switch the hood to the sleeping bag and the jacket or use it alone.

Rich

Are you using a tent or a bivy? What are you using under you? The arc alpinist will work fine at that temp but what you have under and as shelter is nearly as important.

I would be in a tent with this setup

Why don't you call or email Tom at Nunatak and run it by him too just to see what his input might be? If the weight of your other insulating pieces start to add up you might want an arc expedition at 10 ounces more. Or he can overfill an arc alpinist a bit. Jeez this guy will build you a down cheese grater if you want one.
I applaud layering insulation pieces and it works well for me but this is some serious coin to spend so pick carefully,… the advice here given by all is top notch. Good luck.

I pretty much agree with what Mark Verber said. I've taken my Alpinist to these temps without problem using clothing similar to that stated in OP topic. A good pad does help, and be sure to have padding of some sort for insulation for your feet as well.

Another thing I often do in the cool is wear my windshirt with hood over my balaclava to trap in every bit of body heat.

Yep, I've been using my Arc Alpinist in this temp-range a lot. I recently pushed to 12F with the following:
Cocoon pullover (0.6" loft)
shell jacket
two fleece balaclavas
softshell and hardshell pants
32" RidgeRest, misc stuff under my head
Vapr bivy.

I am not a warm sleeper, and of course this was by no means a winter kit! I was just a bit cool, but not uncomfortable. My BMW Torsolite would have been 'toasty'. There was no snow on the ground.

I use a Patagonia DAS parka (1.3" loft in torso) and typical softshell layers w/ a more winter-worthy pad combo to 0F and lower, on snow. This sounds more in line w/ the gear you have in mind, probably warmer.

I'm not familiar w/ the Hyperion, but I would want an attached hood rather than a balaclava – that's just me. The nunatak balaclava is a very nice item however.

EDIT: my Arc Alp has 2oz overfill

With an arc alpinist and a down jacket I'd say you're easily good to 10F on your upper body. As other posters have mentioned, your feet and legs will be feeling it though. This winter, at between 0-10F my legs were feeling cool through an arc-alpinist and two layers of polypro. My feet were wrapped in wool socks and my micro-puff pullover and they were the happiest part of my body.