Originally Posted by
Brennan
I did a short backpacking trip at Pt Reyes National Seashore one summer. I had a summer rated sleeping bag and slept under a tarp. Let me tell you, I spent a couple foggy, windy nights by the ocean there, and I was cold, baby, cold. So your tent and 20 degree bag looks good to me. (My avatar pic was taken during that trip. Yes, I am wearing jacket, hat, and gloves in summer.)
Strange, but I had that exact same experience; I always forget that at most of the Point Reyes camp grounds, the ocean seems to jump up and invade the camp site at night. It really sucks being too cold to sleep. At least I learned my lesson with that one. With a double walled tent, a 20 degree bag might be a little overkill, you could probably use a 30 degree one and save a few ounces, but it's a minimal advantage.