I drove it very carefully home, pulling over any time it overheated. I just drove it to the dealer, being careful enough to drive it on the electric motor mostly, such that it didn't over heat, but the "check manual" and "check engine" lights were both on. They don't have an appointment for me until Tuesday, but they'll try to squeeze me in earlier.
I partly got a new car to avoid the aggravation of repairs (more to avoid the cost). So GRR!!! the car is less than 2 months old.
On the other hand, at least this happened with enough time to get it resolved before I needed to drive to Canada.