Hey guys, I am looking to leave within the next week or two to section the PCT. My initial plans had been to start at KO with the pack, but stuff happens. I had been planning to only carry a bivy through the desert and switch it out for a tent. However, now I am looking to start probably at Kennedy Meadows (sort of with the crowd) and only have my bivy to work with. Are conditions warm/dry enough to make it through the High Sierras with a bivy?

My specific bivy can be found here: http://www.rei.com/product/731431

Also, I have read that people have gotten through with 30* bags, true?