IMO changing ammo between seasons makes sense to me in the midwest.
If I just look at the Winchester Ranger “T” series, the RA9124TP – 9mm +P 124gr might be something I want to use in winter – penetrating to around 13.9” in 4 layers of denim and expanding to .67”, but in bare gelatin it only penetrates to 12.2”
The RA9B – 9mm Bonded 147gr might be something I use in summer, penetrating to 14.7 in bare gelatin, and expanding to .62” But it has penetration of 16.5” in 4 layers denim - a bit much I think and I personally want to see bullet characteristics that hover round 14" penetration.
In this case it would make sense to me to carry the +P 124gr in cold weather and the Bonded 147gr in warm weather.
I’m sure looking at a wider range of ammo can lead to more optimization… but in general it does seem to make sense to me.