The outer layer jacket in winter is a tough call. For this trip, the forecast has changed so that I expect to be hiking out in sleet/freezing rain, so I'll actually upgrade to my Alpha LT.
I'm new to the East Coast, but I think the snow here tends to be wet, as it is in the Sierras. Last winter, I know a Houdini or other softshell wouldn't have kept me dry. I do like the idea of bringing only the Houdini if the forecast is for no or little snow though.
The forecast has warmed up a bit since I put my list together, but I'm actually bringing both jackets because I was to test their respective temperature ranges out. The BPL Pro Parka is new to me, and I want to see how low it can go. I have an idea of the temp range of the Alpine Light, so I just want to know for future trips which I should bring.
I could probably do with 2 Nalgenes. I was mostly bringing the 3rd because I planned on using one for Hot chocolate at night and in the morning and didn't want to waste water rinsing it out to use while hiking.
This was going to be my first attempt to combine two quilts. Now that the temps are going to be in the low to mid 20s rather than mid-teens, I'm only going to bring the Arc Specialist and extend it with my Cocoon insulation. I'd taken it down to 19 degrees with a Thermawrap vest and UL Down inner, and while my legs got a bit chilly, it wasn't unmanageable.
I'll have to wait for another, colder trip to experiment with the two quilt system. However, I was basing my attempt on something I read on BPL, I believe by one of the two Jacks at JRB; it was that you can get a general idea of the warmth rating of combining quilts by taking the temp rating of the lighter quilt, in my case the 40 degree Shenandoah, subtracting that from 70, dividing the result by 2, and subtracting that from the temp rating of the warmer quilt. So for me that's (70-40=30)/2=15. 32-15=17 degrees. I also get approximately the same temperature rating when I add the combined down fill together and look at the rating of single quilts with comparable fill.
Thanks for your input.