People. Do yourselves a favor.
Look around your house, ask a friend for their old one, or pickup a new/used burner cell phone.
If you use iOS, get an Android. If you use Android, get another or an old iPhone, (newer than a 4S). You don't need cell service.
Get a cheap car charger for the spare/burner phone. Put it in the car.
Connect to WiFi, and download a couple of Tesla app to it. Tesla app and maybe Remote for Tesla. Test it.
Setup your regular phone as a hotspot and connect the spare/burner to it once and turn hotspot off. Have it so you know it works.
Pair the spare/burner to your car BT then turn BT off on the spare/burner.
Get a Google Voice account and Google Voice number. Download Google Voice to the spare/burner. Connect to WiFi and make a call to your phone and wife/S.O. so you know you can. WiFi is every where.
Google Voice number cost ZERO monthly. Does not even need to be your regular Gmail account.
(Next time there's a train or bank robbery, you can give them the spare/burner, so you don't lose your good phone.)
Keep the spare/burner in the car or your garage as a backup.
It might make the difference someday to have a spare. But is very handy to test the Tesla app connection to your car easy effort.
Its worth the effort and should cost you less than $20-$30 if you get cheap or used.