Lovely! I'm going to try that. Thanks!

You have to manually tell your HDR application that they're different exposure brackets, even though they'll be roughly the same. The sunlight itself does your bracketing; even though the exposures here were all between 3 to 5 seconds obviously you get much less brightness from a night shot than a day one. If your application assumes they're all the same or similar exposure times, it will not work quite as well.

Thank you for the suggestion. There is so much to learn and so many wonderful and lovely things to try.