Well, I spoke too soon. Yesterday was our first cool morning here in FL. I backed out, and my alarm sounded. All the tires looked fine, so I drove it to work.
At lunchtime, I checked and found one to be a little low. Filled all of them to ~35 PSI, but the light didn't go out even after shutting off the key. But once I rolled out of the gas station, it finally did go out. Cool again this morning, no warning light.
The system works.
