My experience with IMR 4350 was that I saw no measurable difference in mv with my chrono in the temp ranges of 30-50 degrees. When I shot at 70+ degrees, I did notice an increase of approximately 50 fps in mv.
I was taking a 280 out to Montana and was told I could see temps from80 down to 20 that time a year.So I loaded uopsome rounds and put half in the freezer and the other half in my truck.Went to the range and shot the same group using IMR4350