I am going to be using my 20 degree kelty lightyear xp (synthetic) for a winter camping trip that i expect to be seeing 10-15 degree temps at night, possibly single digits.
to help keep me warm, im using my new western mountaineering hotsack, and i have several pads to use (old ridgerest reg, old z-lite reg, new ridgerest solar reg, newish neoair short).
I will be wearing midweight thermals, and i have a down jacket i could use (older rei antifreeze parka in good shape), but im afraid it will get wet if i use it within the hotsack, and i will need it during the day.
I also have a bivy sack and a tent i can use. i was originally wanting to build myself a quinzhee (what i normally do in the winter, which is why i've never needed a bag that warmer than 20 degrees), but this trip i won't have time to build them, so i will be sleeping out in the open. i've only slept one night in it that was in the open in single digits, and i was very cold that night, although bearable, and i would like to avoid that happening again. that night i had just the bag, in a tent, with only the neoair and my old z-light, and light thermals.
right now, im thinking i'll use the two ridgerests with the neoair on top, the hotsack, thermals w/hat, and use the bivy sack. Does this seem like a system that should keep me warm to single digits, or should i just rent a warmer bag or add something to the system? i wont be hiking in very far, so im not really worried about weight or bulk, just keeping myself comfy.
Im going the the ouray ice festival, so it'll be in sw colorado in the san juans