Am I mad to want a 2016 XC90 T8? Aftermarket Warranties?

[BenB]

5 years ago we bought a 2010 XC90. It was 7 years old an cost £13,000. To me this was a lot of money. I'd never spent so much on a car.
Now I'm looking at replacing it, and I'm finding a 6 year old XC90 is £28,000 if not over £30k! This is bonkers, however I still want one!

T8 seems perfect for our family needs. All the short journeys, school runs, anything local would likely me mostly EV only. And the range anxiety issue goes away completely. Having it this way round - EV at low HP for low rev journeys, and a high-HP proper engine for business as usual is more helpful to me than an EV with a gutless petrol engine as an occasional backup (BMW i3 for example).

I've been reading up a bit about the potential problems with a T8, the ERAD failures for example. It's making me think, is it crazy to buy a 100,000 example of a T8?
I've never had one before; is it simple enough to get an aftermarket warranty on an older, higher-mileage car? Do they need proof of service history etc? Would they refuse it? How much do they cost?

Or would people suggest one of the other engines as a more bullet-proof solution?
Would be nice to get some advice! Thanks