As I said in other posts, I am planning a solo camping / backpacking trip to Mt. Rainier, WA and ZIon, Utah. I will be spending about 4~5 days in each place. At Mt. Rainier, I am planning to camp one night at Camp Muir where it can get down to low 30s or high 20s.
My dilemma is sleeping bag – I have a REI halo 40+ which I am not sure will be enough for Camp Muir. I don't mind wearing thick base layer and extra layers of clothing, or even bring a light fleece blanket. Should I resort to this, or definitely go for a sleeping bag in 30+ or 20+?