I took a more brute-force approach - I commented out all references to the largest modules, and re-compiled. The biggest offender, by far, was, not surprisingly, the WiFi code. I am now in the process of moving all of that onto the 8266 itself, which will free up about 15K on the ProMini - more than enough.
It does seem like there must be a way to get an ordered map of FLASH with labels for each data item, function, etc. But from what I saw playing with obj-dump, the names are, largely, the mangled names, which are not very helpful. If I could get a nice ordered map, I could easily write a Perl script to parse it and compile suitable statistics, like size/function, size/class, etc.
Regards,
Ray L.