I did a 700 mile trip as well, but used the same charger location, the best EA charger stop in the US I might add, going and coming back. No issues charging or authenticating. When I went to Chicago I kept getting "power limited by station."
Here is Indy the 38th street exit going southbound on I-65 dips under an overpass and at the bottom there is a stop light. You can be the only car driving 55 mph and come to this light where one car is already stopped. Me personally I would never use ACC/HA to stop me in this instance.