2 - 2 1/2 lbs is lightweight for 15 F to 0 F.
If you are like me, I need at least three, but I have five sleeping systems. Not counting the car.
This is Montana. We have enough in the vehicle for staying in a snowbank, or digging out, or hiking out.
I have been trying to evaluate, realistically, what I want to regularly use.
I miss "winter camping" so that is on my list. That is why I started the thread small wood stoves for "hunter's tents" in this forum.
I like camping out of my kayak. Fortunately, we have big rivers here and campsites are available. I want to do more of that. That is where I will keep my hammock especially handy.
I like lightweight backpacks trips of 4 - 5 nights in The Rocky Mountain Front, here, in Montana. It is difficult to string together 5 - 6 nights "backcountry permits" in Glacier National Park. But it can happen. I need gear that can stand up to highly changeable high mountain weather, but still be reasonably lightweight with all my good food I like.
I like to do a high traverse. I mentioned that.
I would like to try bicycle touring.
I can't think of anything else right now. But, no, I don't need 10 sleeping bags!
Hey, that Sierra Designs possibly "Perfect" sleeping bag doesn't have a "bound buttonhole" sewn into the footbox, does it?
If it does, it is mine!
I had the repair shop at Sierra Designs, Berkeley, CA do that for me for my Choinard Peapod.
You can never have too many sleeping bags Same goes for many other pieces of gear, knives, stoves and flashlights to name a few.