High Altitude Towing

This is for those of you who enjoy a puzzle. A friend of mine towed his caravan over the Alps to Italy and back, The pass he used could easily reach 7,000 feet above sea level and there was snow banked up at the side of the road. He asked me 'should I adjust my tyre pressures, taking into account the change in air pressure and drop in temperature.' If you did that journey would you adjust your tyres pressures?? Polite answers only please.