...when I got there, turned on the camera and got: replace battery. D-oh! I have been so impressed with this new camera's battery life that I didn't even bring a backup! I had the camera in a pouch outside of my jacket for the ride there. So I rested the battery on a cylinder head for a few minutes and popped it back in the camera. Good to go for the rest of the day.
And I kept the camera inside my heated jacket liner, too.
This guy has a great idea for a mailbox. It was a couple miles north of the tag.