I doubt that extremely cold weather significantly affects the adults. However the same probably is t true for the young. Around here (East Texas) a lot of pigs start hitting the ground in January/February. when the “snowmaggedon” hit Texas in February 2021 wildlife was affected all over the state. They had huge speckled trout kills in Galveston Bay and the gulf. Axis deer and black buck in south Texas were also significantly impacted with many reported deaths. In East Texas the hog population was knocked back significantly as well. Mainly to killing off young nursing pigs.
Wildlife in the south are not adapted to cold like those living farther north, so old, weak or young animals can be impacted. During that 5 day period in 2021 temperatures were near zero in places that had never seen that kind of cold in my lifetime. It had an impact, but after a few years they bounced back. The numbers on my lease are still not back to pre-2021 numbers. Not a bad thing in terms of hogs, but squirrels and other small game were possible impacted as well.