All of the ideas about why cold will make a disc fly more stable make sense, however I played yesterday and my results were almost opposite. I live in NE, so maybe location has something to do with it, or elevation.
My wasp, instead of riding a hyzer line, flipped up and turned and just continued straight to the right. Sidewinder flipped up to flat, turned a little more right than usual, but still flexed out at the end. And most confusing was the predator which flew very straight while slightly tracking right for the whole flight, and flexed at the last second to fade 3 feet left before stopping.
My experience suggests here there is more high speed turn and less low speed fade.