Idabooner had a custom made bivy out of canvas I believe made for his bedroll. He'd carry it horseback (wouldn't want to backpack it) and he could just about unroll under whatever tree he wanted. its something I'd like to have done sometime. Wrangling horses you really don't have time for a camp or survival. The last wet adventure I had I just put the tarp over me. Problem I had was the condensation from my breathing was almost as bad as the rain.