I am headed out for a winter camping trip in Northern Minnesota and am trying to figure out how cold my planned sleeping system will take me.
It is currently -18F in the region that we are headed too. We are not going until the end of Feb., but it could still get that cold or colder at that time.
Can somebody give me some good feedback on my numbers and questions??
Referencing Mark Verber's website for insulation values and playing it conservatively...
- Sierra Sniveller Long - 2" Baffles with 2.5" Overstuff -> WM says 20F for 2.5", JRB says 25-30F)
- Lafuma 45F Polyfill Bag (Long) converted to quilt (overbag) - 1" Loft for a total of 3-3.5" -> Verber says 0F for 3.5" (I would probably put the system at 10F)
- Titanium Goat Raven XL Bivy - Verber says 5-15F addition. Due to highly breathable material and non-reflective, I put it closer to 5F Addition (Summing it up, the system so far should get me down to 5F)
- Insulated clothes - Marmot Down Inner Jacket has about 2" loft, BPL Cocoon Pro 60 Side Zip pants are about 1.5". In theory, this should get me down to at least -30F, but I'd be surprised if this was actually the case. I'd also be extremely nervous about pushing it that cold!
I plan on wearing my VB socks in my wool boot liners for my feet. I also have a poly-fill insulated balaclava for my head. Lastly, I will be wearing all my base layers (merino wool).
-Sleeping Pad -> REI Blue Foam 3/8" = 1.4 R-Value, I'm pretty sure the Walmart Pad I just picked up is 1/2" which has a 2.2 R-Value. I'm not actually sure how cold this will get me too, but I would think easily down to 0F. Haven't totally figured this out yet.
Will each layer allow the layer below it to loft fully?? I guess this is one advantage of using quilts, however, the bivy will only allow so much loft as well. I plan on putting my sleeping pads outside of the bivy, so this should help.
Also, I have thought about picking up a down vest to combine with my JRB down sleeves in lieu of bringing the Marmot Down Jacket. Is this worth the weight savings?
Because I have the Sniveler, I can wear that as needed around camp if I decide to swap out the down inner with a vest. Or am I risking too much using my down quilt out in the elements?
I plan on using a Driducks XXL jacket over either my down inner or over the Sniveler quilt. Any thoughts on this?