In my case, I develop loads during winter then use them during summer. For that reason I like the Hodgdon Extreme powders because I am sure that I don't need to worry about pressure problems introduced through higher temperatures. Your situation is the opposite, where any changes will be to a lower pressure and velocity because it's getting cooler.
Since you'll be re-zeroing just prior to your big game hunt in cooler weather, the temperature variation question isn't very important to you.
I've used some powders, like Winchester 748, and the difference in a bottleneck cartridge loaded in winter (20F) and shot in summer (95F) can be a 200fps. Even relatively low pressure cartridges like 6.5JDJ will vary by 150fps using big game bullets. For long shots at small targets this difference can lead to perplexing misses unless you re-zero.