If we assume that the increase in range is linear to the increase in battery capacity, then a standard S85 will go from ~260 miles of range to ~285. Superchargers appear to be spaced 100-160 miles apart. Any gain in time by skipping a Supercharger would likely be offset by a longer stop at the next Supercharger. I could see a slight advantage to those who live in frigid winter areas so that they could gain an effective 20 miles of range, but this may not be enough to warrant the additional cost.
The larger the battery is the longer it will charge at very high rates, so charging to 200 miles of range will be significantly quicker with a larger battery. You wouldn't skip an SC, but you would stay a shorter amount of time at each one. Also, even after the 2016 plan completes (probably in 2017), there will still be many routes that won't be covered by the SC network without going out of your way. Not even one state highway is covered by SCs.
Bear in mind no one needs a 700 mile gas tank either, but many vehicles have them. The hypothesis as to why is because people want to stop when they want to, not when the car wants to. Tesla owners are freed of the trip to the gas station during local driving, so only on trips do they have to stop to charge, and the shorter that time can be made, the happier everyone will be.