I was very surprised at the choice they made, to keep the single-motor S60 & S85 models.
Given that the forthcoming Model X is dual-motor only and the now sizable deployment of Superchargers, I can't help but think that canceling all the single-motor models, offering a discount on options or upgrades to anyone who'd already placed an order ( Call NOW! and get Supercharging at 1/2 price!!! ) or a cheerful refund would have led to an increase in orders and relatively few cancellations.
I doubt the few extra thousand would have made much difference to anyone waiting on a S85 and the range & performance boost across all models probably would have meant an increase in orders. And I can't think of any mass production car in any sane price range where you can lose an entire motor / engine / drive unit and keep on going.