I guess option would be to actually show one more value which google reports along with the map. This can be easily done on Garmin connect website where it maps the data on Google maps it can use Google maps API to report one more value of distance.
Today's run was good as usual it was morning run so I was not at my best but I finished in decent time. I ran out of water again with just one bottle in hydration belt. Next time I need to carry both bottles especially since the distance is going up by 2K again.
Here is how the route was.