My range indicator dropped suddenly from 9 km to O, with 4km left on my trip. Went back to 9 then a minute later to 0 and stayed there. I continued "on a wing and a prayer" and arrived at my destination.
I had shut off the cabin heater to conserve power in below freezing temps. Did that somehow contribute to perhaps a cooling of the battery so the available range wasn't accessible?
And was it running then off the 12V, or....?
P.S. I've arrived at the same rural destination with 1km showing no problems.