RE: Clothes from frost to upper 50s
Lightweight wool pants over lightweight polypropolene long underwear would probably fill the bill. These are breathable materials and have a broad comfort range. They both dry quickly, too. One source of suitable lightweight wool pants is get the M-51 Army wool trousers that can be found on the Internet or through Army surplus outlets. I have used these a lot, including at 10,500' elevations in SW Colorado hunting the Wapiti.
Other sources of such lightweight wool pants would include Filson. Their MacKinaw Field Pants are 24 oz wool and NOT lightweight. They have another pair -- maybe called "featherweight"? -- that would work. They are pretty expensive, though, at about $170/pair.