I don't think the 120 TTSX was the issue. I don't think I have ever missed a shot due to temperature, but I don't shoot at long ranges. Inside 300 - 400 yards it would take a major shift in point of impact to make a difference. I can't verify it but the most I have seen is a couple inches more drop. I think good barrels and bedding contribute to not getting left and right flyers but again impossible to prove. I do have to be concerned with hot weather where even the most stable powder will show an increase in pressure. Either working up to max loads in hot weather or stopping a grain or so under max is usually all that is needed. In real cold weather I keep my spare ammo in a pocket with a chemical hand warmer and rotate it into the rifle every half hour or so if possible. Or if in a stand I just load one when deer are in sight.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli