So would you drive this car down a busy highway at the assurance of this dealership that it is perfectly driveable? Either the battery is faulty, or the car is miscalculating SOC, range, or both. Either way I would be very hesitant to drive it.
I would experiment a bit. I don't think I'd put it on the freeway, but if I did I would stay in the right lane for sure .... might even be with one of those I D 10 T's who go below the posted limit on the freeway. But yes, I would drive it conservatively. I am not lawsuit happy like someone I won't mention. But I would take city streets and take it home. That's what I would do. Other's might escalate with management, call GM, call their local news affiliate and get a loaner and leave it there. But yes, I would drive it carefully, not race with it, not go to the #1 lane on the freeway and be somewhat responsible in my driving. I think both solutions are fine. The problem here is that this highlights the hidden secrets of dealership service that no one will talk about or acknowledge, here's some of the highlights:
1) Some of the techs are horrible.
2) Most of the service writers are horrible.
3) Dealerships want to see you something new and shiny and they lie. After you bought your car, they really don't care about you like you wish they did.
4) Sometimes the dealership as a whole, all the way into the rank and file have lied so much they actually believe their lies as truth.
5) Dealerships that say they have an EV tech, just might be .....dishonest.
6) Even GM doesn't know who's got an EV tech and who doesn't because one thing I know with 100% fact/certainty .... when tech leaves, dealerships take their time taking critical techs off their roster as far as GM is concerned.
7) Some service writers just make poor decisions. I make a few now and then ... daily it seems.
8) People need to get their heads out of their buttocks and realize things go south, it happens, try to not be a jerk.