Thanks for the good and interesting comments. I didn't know if this would be a very interesting thread, but I think this is an important topic for drivers now that I see everyone's feedback.
The summary I am taking out of this is driving below 45 to 50 degrees = caution, below 40 degrees = warning, below 35 degrees = danger. Again, even below 35 the car handles consistently and predictably, but at any of these temperatures, the margin for error goes away. Any aggressive maneuver in steering or braking may not get the desired results.
BTW, this was focused on temp, not pressure, but good info on effects of pressure is certainly not unwelcome.
