I may have told you a fib Bob. I'm a sucker for outlet stores, and I remembered that earlier this year I picked up a new synthetic Mountain Hardwear Hyperlamina Spark sleeping bag rated for 32F (more like 35F). I did not really need it, but couldn't pass it up for the price. It could be a good option as it would save me over a pound and a half -- even if I bought an extra pair of sleeping thermals. The puffy could also be layered on as you say.
I'll think on it overnight.
I see where you are coming from now. I'll be bringing my BCP hard sided Nalgene bottle -- have to show support for the site you know. I have a couple of those Platypus "bottles," in fact I was thinking of using one as a replacement for my heavy flask.