I goofed last night; my "full-sized" image was actually half-sized, due to the demosaic method I default to in my proof processing. So, I re-did the full-sized image with a regular demosaic, and attempted to jpeg-compress it down toward the reduced-size image file size. At JPEG quality=40, I was able to make it 808Kb, about twice the file size of the reduced size image; lower qualities past that gave diminishing returns. So...
...to follow up, here are the two images, rendered by NGDF:
1. Full-sized, JPEG-compression: 40, Width: 4948 Height: 3280, Filesize: 808Kb
2. Small-sized JPEG-compression: 98, Width: 1024 Height: 678, FileSize 414Kb:
So, my conclusion for NGDF posting would be to keep images full-resolution from the camera, but to JPEG-compress the bejesus out of them for posting...