You could always do it with a bit of scripting:
 exiftool  -q -r -ext jpg -if '
     $ImageWidth > 1000 ||
     $ImageHeight > 1000 and
       !print "$Directory/$Filename\0"' . |
   xargs -r0 sh -c '
     for file do
       mv -i "$file" "$file.bak"back" &&
         convert -resize "1000x1000>" "$file.bak"back" "$file" &&
         touch -r "$file.back" "$file"
     done' sh
Here resizing the images so they bitfit into a bounding box of 1000x1000.
- exiftoolis used to find the images that need resizing
- convertresizes them (doesn't touch the exif info)
- touch -rrestores the original timestamp from the backup file
 
                