We drive the SoCal gusty winds all the time. Gusts can often exceed 60mph. There are plenty of photos of big rigs on their side on the Cajon Pass. I've driven on a head wind that made my awning vibrate on the rig. The answer is not in tire pressure, it is speed. Just slow down. Sometime you might have to drop you speed to the 40-45mph range. Think back to high school physics, you have the vectors of your speed plus the angular velocity of the wind.( or something like that, it's been a long time since high school physics). Anyway, slow down and enjoy the drive.
