As for the "you will want to drive this car more" comments....not really agreeing with that for the OP. He drives the car 60-70 miles daily. I doubt that he will want to drive more than that.
Maybe not during the week, but on weekend, longer drives are a definite possibility when the car is so much fun to drive. I only drive 40 miles round trip for my work commute, but I've so far averaged 2000 miles month.
I could not have made several of those trips with a 60kWh battery. A couple were hard with the 85 since the Superchargers are not all in place yet.
In the grand scheme of thing spending an $7000 on the 85kWh upgrade is not that much and will be more than worth it over the life of the car. In 10 years, when the pack has degraded somewhat the 85 will still get you to the superchargers. The 60 is going to be hard pressed to make it unless you are driving 55MPH. I plan on keeping my Model S for a very long time, so the 85 will keep it viable long into the future.