I'm doing more and more backpacking after many years away. There is a big diff in the amount of bag required to keep you warm at 25 years old vs 50 years old. So far I've learned that a) I need a good night's sleep; b) I really don't want to spend twice as much for a bag that's 30% lighter; c) the extra 20 lbs around my midsection makes attempts to trim ounces in pack weight a little bit laughable.
The magic solution so far has been to limit my range and lower my expectations. And rest a lot. For a bag I use the Intermediate milsurp bag system with a light, medium and bivvy. That way I can often simply leave portions of the bag at home or in the truck.
