I was thinking of the Top Gear episode where they took a standard production Jaguar S-type on the ring and asked Clarkson to do it in under 10 minutes. So not a special car at all.
So are you now saying that the Model S is not capable of driving flat out on country roads for more than 10 minutes ?
Inside Line noticed a 0.3 second difference between their first and last runs while doing 0-60 mph 6 times in a short period of time. IIRC that's A LOT better than the Roadster so the cooling system should be up to the job but it definitely looks like motor power is throttled (no pun intended) when it's pushed hard enough. It's yet to be seen what those limits are but it's not unrealistic to expect that overheating could become an issue.