As I mentioned, I winter camp. I not only carried my pack, I also have towed a sled with most of my stuff in it. I am by myself, so no sharing the load with anyone. It is all a matter of how comfortable you want to be. In my case, the answer is "as comfortable as possible" given my gear. Could I get along with a lot less? Probably. Do I want to? Not really.
Don't get me started, you know how I get.