Hey everyone, so over the summer I purchased a 40° north face Wasatch sleeping bag (anybody have any experience?) And I haven't had the chance to use it yet. The nights around here have been hovering in the mid 40s at night and I want to test the bag out on my next trip. What I want to know though is how you can add a few extra degrees if I start to get cold at night? I have considered getting an sol bivvy to hopefully add a few degrees but I wasn't sure how it would do. I was looking for something light that I could throw in a pack just incase it gets too cold. Thanks!