I think the future of the S depends on how Tesla wants to position itself in the market. They enjoyed having minimal competition for a little while. Now they will be forced to adapt as the competition continues to ramp up across the different segments.
The S is kind of a tweener, right? An offering priced at the low end of the luxury segment, but not competitive in terms of actual luxuriousness, based on what the well heeled customers in that segment expect.
Tesla has some time and plenty of funding to adapt and thrive, IMO. But will they adapt or will they actually believe their own BS and behave like IBM once did, getting overtaken quickly as competition heated up, then having to reinvent itself to stay alive?