My advice, and yes I've posted this mantra on several other sleeping bag threads, only sleep in all of the clothes that you brought if (A) you don't have a sleeping bag, or (B) the bag you have is no where near adequate. Wear minimal clothes inside your bag, like a dry base layer and dry socks. To be warm in your bag your body has to be able to breathe freely and circulate warm blood. Getting good circlation to your extremities is essential for staying warm. If your body is radiating heat, a good bag will retain that heat and reflect it back to your body. Your body and bag have to interact. Excess clothing can constrict breathing and circulation and interferes with that interaction.
My experience has been 180 degrees opposite from yours, provided that my bag was cut full enough to accommodate heavy clothing. In a bag that is too small, wearing all your clothing can be restrictive, and you don't get the full benefit of the extra insulation. However, in a bag that is more fully cut, I've found that I sleep much much warmer with all of my clothing on. Whatever benefits I might gain from my body and bag "interacting" seem to be small compared with the benefits of the extra insulation provided by my warm clothing. (plus, my clothes tend to dry out overnight, which is better than having to put on frozen damp clothes the next morning.)
That's my experience. I'm not saying you're wrong, just that your solutions are not universal. However, I'd guess that most folks who do a lot of alpine climbing in cold places factor in their clothing as part of their sleeping system.