Three cheers for County Electrical Contractors, who were able to come first thing this morning to figure out what was wrong with our upstairs electricity.
The very pleasant electrician, who had to drive down from icy Peru, discovered that the affected breaker had "gone bad," which is apparently unusual. He replaced it quickly, and voila - we have lights and working outlets upstairs! I'm so thankful that it wasn't a complex and expensive problem.
Electricity is one of those things that you appreciate more than ever when you have to go without it for awhile.