Not sure what part of TX your in, but being in central MS I decided to get mine two days ago. Made that decision due to the fact that by the time they can go out in the coop the weather should be perfect.
Ah, Aggie Land. I would say our climates are about the same. I think the weather would be fine by the time they get outside. I also didn't want to wait another month or so for some eggs.
I am in Brenham so we have the same weather. It looks like this winter is mild (at least so far). If you get your chicks this month, you might be able to move them to their coop by the middle of March. I guess the question is how protected is your coop? is it insulated? we might still get some freezing temps before the winter is over. My coop is insulated but mostly for the awful summer heat. If you have electricity in your coop, you can always add a heat lamp in case it freezes since the chicks will be too young to be exposed to very cold temps.