Did I go overboard on a sleeping system for 0*?

Even with those layers, unless you're a warm sleeper, I think you'd be just at the limit with the 30d quilt at 0. I can take a 32d WM Summerlite to 5-10d with a WM Flight Jacket and WM Flight Pants, but then I'm not dealing with any draft issues and I sleep warm. I might be able to take it to 0d with my RAB Neutrino, but I think the lack of a draft collar will eventually hurt. (Actually, Monkey man and Mirage and 3.5oz fill pants… I think you'll be ok…)

Underneath you, a CCF pad and an XThrm will be more than plenty though; I like the redundancy aspect of a CCF pad in winter, but I've found a Ridgerest + Prolite 4 or Ridgerest + NeoAir XLite will both easily work to 0d, so a CCF and XTherm will keep you wholly insulated from underneath.

What is your hood/balaclava solution, given you're quilting?

Have you considered using both the 30d and 40d in combination as a winter quilt system? How much more than the 10d would that weigh?

This is where backyard gear testing, alas, comes in superhandy. It's so hard to guess what may work for others.

You probably want a 20 degree quilt :)

I took a 30 degree EE quilt down to 9 degrees two years ago and was fine; I remember not being cold, but not warm either. 9F was outside air temperature. Inside my tent, it was a few degrees warmer. I wore less insulation than what you have (no down socks, no down pants) and slept on a Nemo Zor only.

If you are truly going down to 0 degrees, I think the extra warmth of the 10 degree quilt would be nice to have and provide you more margin of safety and comfort.

So, I'm the type of person that buys everything….tests things out, and then sells whatever I don't think is optimal.

For the head….I was planning on using a wool buff, plus just the mirage hood.

I can also bring to the table:
Goosefeetgear down hood (zpacks hood)
Katabatic gear crestone
Black rock gear down hat
various fleece balaclavas

Yes, I have considered cancelling my 10* quilt order…and using the 30 and 40. That would be 20.5oz of down, which on EE's spec chart, is the same as their 0* quilt. However…that would be a 6oz weight penalty of extra fabric for a second quilt. Total weight of 40* and 30* is 32.61oz.

A 10* reg/wide quilt that I ordered is 23.75oz.

Not to mention…that if the 0* quilt is too warm for my extra down layers (mirage/down pants) then I don't get to take advantage of the mirage/down pants that I am bringing anyway for in-camp time.

Is 0d the lowest you'll see, ever? If so, I agree with John – I'd buy a 20d quilt and layer with the Mirage and Goosefeet pants. That'd keep you comfy and give you a little margin, I think. Maybe a 40d and a 20d and sell the 30d?

Heh, a 0 degree bag combined with a down jacket and down pants would keep me just right at 0 degrees.
I use my 10 degree quilt at freezing.
I get cold easily.

Well…whether 0* is the lowest I ever see remains to be seen on how much winter camping I'll do in the future…but even if the forecast is a low of 0*, there is always going to be fluctuation in the forecast, or difference in temperature simply on where I happen to be camping, or…etc.

Basically….with the mirage and the down pants, conservatively, for a normal sleeper, you would say that would be at least 20* in added warmth?

And, with the mirage hood and buff, do you think that is enough with a quilt or should I bring like the black rock down hat?

Basically….with the mirage and the down pants, conservatively, for a normal sleeper, you would say that would be at least 20* in added warmth?

I don't want to generalize, but for me, personally, the WM Flight pants and jacket (which are substantially less warm than the Mirage and the Goosefeet pants) add somewhere between 17 and 22 degrees to my sleep system. So yeah, for me, that'd be a safe assumption.

I think the Mirage hood would be enough, but I have never actually seen a Mirage hood in real life, so again, totally guessing.

I'd use a Ridgerest pad. Your 1/8" may be a bit too thin with that skeletonized X-Therm mattress. I have a 1/8" pad of floor underlayment and I'd never use it for winter camping.

Otherwise go 10F. colder than the "advertised" temp rating of quilts. By 2 Am your body temp and outside temps both drop, making a warmer quilt a really nice thing to have.

I can't speak to your quilts, as my only quilt is a 30*, and I'm a cold sleeper. I have a 0* synthetic bag and I froze my butt off at 15* with it.

But I do want to mention the fleece balaclava called the Seirus "Hoodz":
http://www.rei.com/product/725706/seirus-hoodz

Ever since getting this, I've been much more comfortable in cold weather camping. A cold nose makes me miserable when trying to sleep, and most balaclavas I've tried make me feel like I'm suffocating trying to breath through them. This hood has "ports" that you can adjust around the chin area to place over your mouth, while still keeping your nose warm. It's very cozy, and will be with me on all cold weather trips from here on out.