Do you have 42 PSI on all 4 tires? I have 42 on the fronts and 39 rears. 20" studless snow tires. What's your tire size? Just wondering whether I should try the same settings front and back.I fiddled with the car a little more. Tesla P85D had a recommended tire pressure of 45 PSI - hence all the data in the graph are at that pressure. I decided to check what happens with the Taycan at higher pressure - went for 42 PSI instead of 39. In addition, I charged to 100% just before departure. With these 2 changes there was a ~5% improvement (395 Wh/mi at 30F vs 405 Wh/mi at 40F).
The ride comfort was not different at higher tire pressure - as far the seat-of-the-pants measurement. I will stay with current setting for a while, will see what that gives in really cold weather.