You know, I recently considered this. In October, we left Spring, Tx (elevation 121' at 70/80 degrees) and drove 2 days to Portage, Pa (elevation 1,800' at 28 degrees) and the TR3 didn't seem very happy about it. (Actually it did ok, but seemed sluggish and not at all zippy on the hills.) I had a float sticking, and after returning found the points wiper had worn until I couldn't see the gap, but I've been wondering about the stalling issue I had while up there. The TR3 ran like a champ down the highways, but it seemed every time I pulled off a highway and stopped for any reason, the car would stall. It always started up as if nothing happened, but no matter how I tried, it would stall if I came to a stop immediately after a highway run. I chose to stick with the later portion of that quote, and before I got home, it returned to normal behavior. Perhaps an O2 sensor would have been helpful, but I'd need some more sense to use it.
I prefer a more definitive approach to adjustments, where something is measurable, like seeing the color change on the color-tune, than waiting for 'pinging in a high gear at load'. My imagination takes over and I don't trust it. For now, I'm sticking to the idea that my TR3 prefers warmer weather. I was a little more sluggish, slower and had trouble breathing up in the cold -the TR3 and I are alike.