It’s really hard to find some lethal temps on most species. I know large pacu can handle some lows but will eventually die around 45.5f. Keep in mind air temperature and water temperature can vary quite a bit especially if the pond is in the ground.
I think arrowana would be the most likely to struggle and die at those temps.
There are some species that could handle your winter temps. Native bass, sunfish, gar, and channel catfish. The albino channel catfish are pretty interesting and easily can grow over 2 feet, and are more open water swimmers as they age. You also have those rio grande cichlids in Texas might be something to look into if they can be collected locally.
Hybrid striped bass may be a good alternative to peacock bass. Not as colorful but readily eat pellets and hit the surface while feeding with a punch. They also get huge. I have them in my pond and really enjoy them.
Maybe have a temporary pool type pond in the garage or a heated space and take your monster fish in for the winter??
This is a intex pool I use to start my smaller fish before sending them outside