Q.Acacia Tree
I have an Acacia tree in Comfort, Texas. We had some very severely cold weather in December, temps in the teens and strong winds. The leaves were green until then, turned brown and fell.
So far there is no sign of growth on the tree. Is it likely to be dead?

It's best to wait a few months at least before deciding whether the tree is dead. It might eventually put out new leaves as it recovers, and once this happens, you can prune out any dead branches that don't regrow leaves. You can also check whether the tree is dead using this method:
https://www.gardeningknowhow.com/ornamental/trees/tgen/tree-scratch-test.htm