As Hikermor says, a good reflector will utilize your fire much more efficiently, necessitating less fuel. I have spent more than a couple of nights in a debris hut of mostly pine straw (the thicker the better) with a good bed of pine straw under me, a good fire and a reflecting wall on the other side of the fire. It works very well.

Ron Hood (RIP) explained well the science behind heat loss. He also discussed how to find the best shelter at different times of the year. His videos were good. I believe his wife is still marketing them. It is a lot to put in a thread, but if needed I will try.