Your wrong here
It was not the snow, it was the Mighty Soviet 58th Army(best equipped/trained Soviet Formation) mobilized and parked opposite Lop Nor. In 1971, the Soviets lost patience and were getting ready to annihilate the Chinese from the face of the Earth. The threat was real, the capability was real, the Chinese Intelligence were convinced they were going to be attacked soon. The pace of Soviet buildup and Armoured Manoeuvres were something the Chinese could only watch with aw and envy. To give you an example of how scared the Chinese were, they moved their defences back 100km to avoid any encirclement battles on the border. Thus, they seceded 100km of their territory without a fight.
The Soviet 58th Army staring you right in the face is far more scary than the Indian Army overrunning PA's defences in EP.