In my daypack I have a 2# thinsulate mummy bag and a 1#bivy as had been suggested to me. Three pounds and fairly compact. That's not much weight considering the alternative of using a space blanket alone. Add a beanie and a heat pack or two and I'm confident I'd survive anything but deep winter here. A cup of tea and a candy bar or meal before turning in would also help make the experience warmer and more comfortable. JMHO.