I got my wish yesterday: the wind direction remained constant. I had a very strong tailwind coming home last night. The temperature fell over the day, but it barely mattered. I rode really really hard, and only my hands got a little cold. My feet only got cool. The rest of me got very hot. With the tail wind and my added effort, I really flew.

For no particular reason, I brought my battery powered headlight and compared it with my Dynamo powered light. The latter won. It's a Philips Saferide. Very nice beam shape. The battery light is a B&M Eyc IQ2.