i can snag a lightly used black diamond tripod bivy for reasonable coin... what do you think about those?
heavier than my contrail, but would work better in the snow i think.
of course, the contrail could work - it would just need me to setup under trees or something in case there was chance of heavy overnight snow.
but i don't know how that bivy would perform with a big dump of snow either.

i have a 30d bag, and a Big Agnes insulated air core pad, rated to 15d. i've used that to sleep in a lean to down into the 20s with minimal extra clothing, and nothing over my bag to block any wind. pretty sure i could go colder. guess i could test out in the backyard.

should i snag that bivy? it would create a micro climate around me. but with a down bag, not so sure that is a good thing.