Last updated 06-Oct-2021
If the car loses all power, perhaps through an accident, the electric door locks won't work. In the front this is less of an issue. The earlier MS and MX the door opening level would still work, and on the M3, MY and latest Model S, as well as the door opening button, there is a lever by the window switches (which many a passanger has used inadvertently). Getting ur the front of a Tesla therefore poses no real threat in the event of a complete power failure.
What is not so easy is getting out of the rear of a Tesla in the event of a power failure, and we would go as far as saying only the pre 2021 Model S gives you a fighting chance to do this at all. Of course any car with rear door child locks is in the same position, but should you be an adult in the back, it can be a cause of panic if you were trying to exit.
In the pre 2021 Model S there are a couple of release switches in the front of the seat base. These just need to be slid to one side to spring the rear doors. It may not be the easiest thing to do and not something you'd immediatly reach for, but it can be done.
The Model X cam in theory be opened from inside as their is a mechanical release, however this is situated behind the speaker grill in the door and with the best will in the world, this isn't something you'll be doing in a hurry. The Model 3 and Model Y have no manual rear door release.