I've been wearing Teresa's wool for a while now. I've layered it many ways. One thing I wanted was a light insulating layer that would fit in my haversack. I unbuttoned the liner from a M65 field jacket and crammed it into my haversack. It worked extremely well. It looks like it would be noisy but with a layer of wool under it and one over it really isn't. Just put it on when you get to the stand. It would also be easy to add a few buttons to the jacket to button it in but I didn't need to.
I've also been committing another taboo by using some cotton. My father in-law was dairy farmer and worked outside in some very extreme conditions. He always wore a thermal sweatshirt. I have been using one of these as well. When kept dry these insulate well also. I had tried a high end "Modern" synthetic sweatshirt and it was one of the coldest garments I had ever worn, I gave it away.
Both of these can picked up for not much money and work well.