Going back to things that work though, I recalled our research on the different yurt companies and their methods of insulation. To my mind, the most common insulation offered by modern yurt manufacturers is Reflectix.
I recalled that when I was inquiring after space blankets for the ceiling Maier Hardware had suggested that they did have Reflectix, so I called them and quickly determined that they also had the best pricing per roll.
I bought their entire stock of two rolls and yesterday we set about installing them in the large yurt.
First we pulled all our items away from the walls of the large yurt. This was a great chance to sweep and dust the floor in behind!
Then I pulled both rolls around the perimeter. Every three or four sections I had to pull the wrap out into a loop, as I found the friction to be too great to just pull the roll around the entire outside wall in one go.
This morning it was cold again, but that was after not having put on a fire for over six hours. Donna sent me to warm things up, and it took about a quarter of the usual time to do so. In half an hour the large yurt was quite comfortable - that normally took about two hours!
So anyway, after a sample size of one evening, night, and early morning, I am feeling very hopeful that this new experiment will be just what the doctor ordered.
As a side benefit, I can't help but think that this layer of protection will also help keep down some of the lint in the yurts - the felt is great to look at and natural and all, but it did constantly shed small fibres that we were picking off the floor, ourselves, and our plates.
I will consult with Donna at breakfast to see if she thinks that we should apply the same treatment to the bedroom yurt.