I do the majority of my camping in the Sierra or extreme southern Cascades. You are hitting the shoulder seasons, where, on some trips, a summer bag may be ok for the weekend, but things can change in a hurry. I have used my WMCaribou bag on mid Spring snowcamp trips and in the Fall. If you have a good warm coat, you can get by. I have been out in mid Oct. and had temps in the mid twenties but I had a 25 degree bag. You may be asking too much out of one bag. Also, the rule of thumb, is get a bag, ten degrees warmer then what you expect to be exposed to. A 15 degree bag for a 25 degree trip, etc. I have had my 5 degree Antelope Super DL on a mid Spring trip and the overnight temp only got to 32. I was roasting when I went to bed, but the down will adjust, so I only suffered for a few hours. By morning I was fine. Enjoy your shopping and decision.:)