Which combo of Jacket and Vest

I assume you are talking reasonably cold weather, right? The combination I like is a montbell thermawrap vest paired with a patagonia micro puff, though the Cocoon pullover would be a fine choice as well.

My standard winter trip has the days which range between 10j-30F with the nights dropping to between -10 and 20F. In these conditions I typically bring a Patagonia R.5 base (mid to heavy weight), warm hat, neck gaitor, an unlined hooded wind shell (patagonia essenshell – EPIC fabric, or dragonfly 3oz windshirt), a Thermawrap vest, and the patagonia micro puff.

I have found that depending on wind I can be comfortable when active in my base + hat + (either the windshirt or thermawrap) down to around 20F and the combination of the two down to around 0F. When sitting around the combination of vest + windshirt keeps me happy to around 20F.

For me, the micro puff is way too warm when I am active until it is below 5F, and too warm sitting around if it is above around 35F. So I use the micro puff during rest stops and at night when I am not really active. If it gets suprisingly cold I sometimes wear base + the micro puff when active, and the thermawrap vest and micro puff once I stop.

Of course, these temp ranges assume I am not wet and have had enough to eat / drink. Compromise one of these things and and the comfort ranges change.

–mark