Where to carry your stuff in cooler weather is one half the problem. The other half is the gear itself. Montbell, a Japanese company makes some super light weight jackets. an have I have an older model that weighs 8 ozs, just a bit more than a Tee shirt. The newer models, such as in the link weigh 5 or so ozs. and I know they pack very small and are very warm with a layer of insulation. https://www.montbell.us/products/dis...06686&gen_cd=1