Check with the manufacturer. If they don’t provide specifics I would avoid water that is higher than the underbody.
The Rivian water depth is 3 ft per manufacturer.
I would only trust documentation from Tesla on your model.
However, in a bad situation, I wouldn’t hesitate to take a Tesla up to the bottom to mid-doors. Getting the batteries wet would worry me, but there is a decent amount of sealing they do.
I would also likely figure out where the electronics are. I came up on a F150 that tried to cross a creek and a little bit of water came in the door and got the space under the seat wet. Couldn’t start it after. I’d get familiar with where the fuses, switches, and anything else is and see how well they are protected.