Winters on average are temperate. But it may be very cold, or be really really nice in any part of Texas. We live just north of the DFW area. Any given day in Dec/Jan/Feb may be in the 50's/60's, even 70's. Or it may be 15/20 degrees with ice and/or snow. Two years ago we had a major ice storm in mid December breaking trees and power poles and shutting down highways.
I have hunted in the hill country near Fredericksburg every year since 1969. In past Novembers I have hunted in shirt sleeve weather. And I have hunted in freezing weather with ice and snow. In past Decembers I have hunted in 60 degree temps. And I have hunted in as cold as 12 degree temps.
No way of knowing more than a few days in advance what the weather will be. And it is not unusual for it to be 65 one day, 25 two days later, and 65 again a few days after that. And likely followed by cold again shortly after.
The hill country has some of the most scenic areas in Texas.