I spect 20-18 F at minimum, mostly 28-25 F, only at night and early morning.

I use for power up my sleep system some times.

For first layer:

I use or minus 33 merino wool

http://www.minus33.com/catalog/kinsman-midweight-turtleneck/712DH

Or mammut

http://www.backcountry.com/mammut-moench...MAM0773-CYA-XXL



Shell i buying Z packs rain jacket.

http://www.zpacks.com/accessories/wpb_jacket.shtml