Pessimistic is an understatement at best......I think @Zimm is being pessimistic, the build a vehicle for utility and keep it going long past it's "best before" date path has already been well trodden by Rover, British Leyland, Austin Rover Group and JLR, called variously Land Rover 110/90/130, Defender 110/90/130 from roughly 1982 to 2016.
Ineos Automotive have 10 years of BMW engines contracted, so what happens in roughly 7 years time will be interesting.