Sleeping bag rating for spring ski touring in PNW?

similar here. Marmot Nightowl bag, Polarguard 3D, 30-35 F rating, compresses small. Puffy jacket. fleece pants in colder temps. Ltwt simple bivy sack.

My girlfriend and I just bought a "doubler", which converts a 1-person sleeping bag to a 2-person w/ minimal weight addition, by zipping into the open bag. The company that sells them is closing out because the zipper standard is changing, so it will no longer work w/ the new zippers. The upside is that their products are selling for half-price, I think while inventory lasts ( www.functionaldesign.net/about.htm )

We field tested it last weekend and really liked it - going w/ a 20 degree down bag, we bought the lightweight doubler (45 degrees I think), figuring that the "doubler" part would be on the ground side so it didn't really matter how thick it was, using the warm bag part on top. This all assumes, of course that you have a tent partner that you want to sleep with

Speaking from personal experience, be careful what you have for dinner if you're going to share a double bag or bivy. My wife still makes fun of me...