Oh hey I just figured out a little trick. In inkscape:
Select all.
control-K (now they are all one path)
While this new mega path is selected, go to Extensions-Visualize Path->Measure Path.
This will give you a total length of paths.
Undo undo undo to get back to your correct path divisions and colors and whatnot.
Now look up the speed of the GF in real measurements, which is … being difficult to find. Is this the correct thread?
@shop, @jbmanning5, etc. You guys will know where to find that conversion right?
Anyway, get inches per minute form whatever link they find for us, and then you should be able to algebra yourself to a pretty good estimate?
PS:
This is completely untested and may be terrible. it just seems promising.