RL-17 works well with the 129gn Hornady SST when the temperature is 35 degrees. What it grouped at 65 deg was the same at 35 deg., so I'll take that as a good sign.
It is amazing in my 22-250, but I did chronograph (magnetospeed) a fps loss of 1 fps for every degree of difference from my initial load at 60 F. I chronographed a few rounds (left in the car overnight) when it was near 0F and the fps loss was 1:1. It hasn't been hot enough here for me to try it in warmer weather. But maybe the increase of volume will help it stabilize in larger cartridges?
...say that is looses 1fps/ 1*, @ 500yds. w/ a 70* shift in temp. you'ld have less than 2" more drop & about a 1/2" more windage. A difference in altitude density can cause bigger shifts, so personally, I try not to overthink it...