If fruit tree flowers buds have begun to swell - and these have - then they are most vulnerable to freezing temperatures. Unless the temperature decline is quite gradual - and this doesn't sound like it will be - I would expect damage to the flowers and many will abort. And even a gradual decline is no guarantee once the buds are beginning to show any color.

You really should not see any damage at that bud stage with those temps, unless they last for many hours. I have found the link below to be the best resource with this info, and I have had many peach crops after high 20’s even during full bloom.

http://treefruit.wsu.edu/article/critical-bud-temperatures/

As long as your trees are rated for North Texas, permanent damage would be rare. Peach trees in the Hill Country have endured drastic temperature swings for a long time now. When was the last time a freeze in February wiped them out?