Merino wool - all first lite and then if i feel cold i'll throw on a wooltimate henly with windblocker in it. I usually do not pull out the wooltimate pants until nov or if it is really cold and i'll be sitting or in a tree stand. Yes wooltimate is heavy but wow is it warm.
I have used a Windblock fleece vest for the last several years in similar temps up here in AK (mine is made by marmot, but almost every company makes some version). I have found I don't usually need a long sleeved mid layer, as the vest keeps my core toasty while still maintaining the ability to zip up or down if I am too hot or too cold. When I actually stop to rest or glass I almost always put on my "puffy jacket" aka insulation layer anyway, so I haven't really missed the sleeves. Really cuts the breeze when I am hiking, and when I slow down it adds another layer of warmth inside my insulation layer (Integral Designs Rundle jacket). I recently acquired a Sitka Kelvin vest, so I may give that a spin this season.
arcteryx Atom LT pullover for my puffy insulating layer. I also use some thicker merino, this year im also going to try some thicker merino from kuiu instead of my black justin charles stuff. That acrteryx puffy jacket is warm though! packs down tiny, and only weighs 10 ounces.