It is true that if you want to drive to Mountain View at 85mph you probably can't do two round trips, You could certainly still do one round-trip without thinking about it, especially if you charged in range mode before heading down there. Actually from your figure of 200mi range, maybe you didn't know about charging in range mode? That gives you about 240mi range (maybe a little less with an older battery).
The issue about driving speed is just that, as with any car, wind resistance applies dramatically more force to your car as speed increases. If you are driving 60 (which is at or above the speed limit on 101 and 280), it is not bad since you are about at the efficiency the car's published numbers are based on, but if you are driving 70-75 range is very much decreased.
Here is a range vs. speed graph for the Roadster:
(There are more-detailed charts on the internet if you search for them). Notice that if you are driving 55, you get about 70 more miles of range than if driving 75!
On the other hand if you want to drive 45 and feel like a total ass then the car will go really far!
So this is definitely one thing that will improve as electric cars and infrastructure get better: less dependency on speed or weather conditions (driving through heavy rain will also decrease range by quite a bit). In a Model S with the supercharger network already in place, you could probably drive from SF to LA like a bat out of hell and not worry about it, which is cool.
But, I am just saying, I drive round-trip to the south bay all the time and do not think twice about it. That is the kind of range that is trivial for the Roadster. Unless you commute at 90mph and aren't using range mode and/or didn't charge the car all the way up.