Earlier quoted context omitted.
By the time they are available, your Tesla will likely be due to replaced anyway. But here's to the future, fellow EV'er.
Deliveries of the Taycan start this year
EDIT: "Prices for this ‘Turbo’ launch model will be around £130,000 with cheaper/slower versions kicking off around £65,000 within 18 months of the car’s launch in late 2019. "
So... maybe we'll see some in 2019, but really it's 2021 before more than a few thousand hit the market.