Hi all,

I need some help choosing a good sleeping setup (or knowing yours). Last year I was out and an unforcasted cold front came in and the temp dropped to -20F. Wasn't very prepared and paid the price in discomfort and lack of sleep.

I'd like to invest in a nicer sleeping bag. Looking at some down ones comfort rated to -20°F or -40°F with pertex exterior and interior. (Leaning more towards -40, <1lb difference, <$100 more). The big question: managing internal condensation???

I've seen some people say to pair a down bag with a synthetic quilt so that the dew point and moisture is frozen in the synthetic fibers and not the down, or to add a vapor barrier inside. Are $500-1000 sleeping bags really not sufficient on their own? I never sweat overnight in the winter and will breathe outside my bag in a well ventilated tent or tarp cover.

Consider this sleeping setup:
-reflective, waterproof 'tarp', closed cell pad + air pad (r-value 5+)
-merino wool base layer, heavy socks, gloves, hat, balaclava. (Designated for sleep)
-sea to summit thermolite reactor extreme (for comfort and a little warmth)
- -40°F down sleeping bag OR -20°F down sleeping bag + synthetic quilt?

What temp rating should a quilt be to work effectively? Is 50° sufficient to move dew point? What range would the -40° down bag and a 50° synthetic quilt give me? Or -20°F + 50° quilt?. *I don't plan on camping if forecasted lower than say -15 at night, but want to be ready for unexpected cold fronts.

Thanks!

I'll just share my -20 sleeping gear fwiw.
Exped DLX9 pad. Wonderful. Snow under till crunch, no melt. An LLBean synthetic rated -20 but never been comfortable below +10 or 15. A Marmot down rated 30 degrees. A sea to
Summit liner. Flannel pajamas and a balaclava. I sleep on my stomach with arms crossed under my head so have a wool blanket I wrap over my head and arms. Most important - down booties from REI. I can get up in the night to go pee and just as comfortable when I get back in. Hardest part is getting up in morning because I'm so toasty.

Goes without saying nothing I've worn during day is in sleping bag and sleeping bags are aired out during day.

Been to the negative teens with a BA Pomer Hoit 0 degree bag and Exped 9. Sleeping in long wool underwear, socks, balaclava and liner gloves.
There is no set answer for you personally as everyone has different tolerances.

butthead

When it's really cold I use a Mountain Equipment Glacier Expedition bag with a Thermarest XTherm Max and a half-length z-rest and have been good down to about -30 and think it could go a bit lower if needed.

I have a VBL I made myself as well, but usually only find the VBL helpful if you're going to be out for a prolonged period of time (like a week or more). They do add a little warmth for very little weight, but I find them to be uncomfortable especially getting out of it in the morning... Don't breath into your bag and don't overdress/sweat and you should be OK for most trips that people take.

I think adding the outer synthetic bag would be more helpful in a situation where moisture from outside is a risk, but I've never bothered as the weight penalty is considerable and I use a long bag to begin with so finding a couple bags that nest perfectly hasn't worked out yet.

I also use an event bivy bag and that's kind of become my go-to for winter camping and I forgo a tent unless I'll be in a place where I know there's a good chance I won't find a sheltered area. I find the bivy bag keeps me noticeably warmer than sleeping in a tent but you have to watch/manage the moisture and again try not to be too warm (IMO just as difficult as not being too cold and just as important).

For what it's worth I really like the Mountain Equipment bag and they can usually be had for more reasonable prices than feathered friends, western mountaineering, etc especially if you can order from a country with a favorable exchange rate. I think I paid <$400 for mine and just had to wait longer for shipping.