Looking at bags, as my current one weighs 4 pounds 10 ounces, which is a tad heavy to carry 2600 miles. Planning a 2018 southbound hike as it fits my schedule a lot better, which is why I'm wondering about this. I've heard that you generally need a 20 degree bag for the PCT mostly because of the Sierras, but since I'll be going southbound, I'd pass through the Sierras in September. Would I still need a 20 degree or could I get away with a 25 or 30 degree?