Got a trip coming up that is forecasted to 19°, probably 15° at elevation. 2 man trip. 7 days. Here’s the situation:

College students. We’re working on a budget. We’ve got a 20° and a 15° bag. Also have my girl’s 25°. Obviously the two bags alone are not near warm enough. Planning to wear our puffies, down booties, balaclavas and fleece base layers. From there I’m seeing a few options to warm up some more: bring the extra bag and lay it open over both of us; buy a down quilt to lay over us; my personal fav currently- $15 for two mylar rectangular bivvies we could just slide the bags into. I know the condensation is an issue if it’s too warm. I could just cut them into blankets perhaps? 2.8oz each… super compressible... anyone seeing a flaw here? Tell me if it’s dumb or smart. I’ll be test running whatever I do before the trip, don’t worry.

Feel free to roast me for considering a non-ultralight method here with an extra bag. Just being preemptively mindful to not turn into an ice cube. Thanks for the help!