You will of course need to eat on your trip I recommend Pappadeaux's Seafood Kitchen. More Louisiana Cajun than Tex-Mex, but culturally relevant to the TX Gulf Coast and great. They are in all three of your cities and can be located on the attached link. I used to go to the one on Rt. 59 SW in Stafford just outside of Houston. Highly recommend the Crawfish Etouffee & Popcorned crawfish mixed platter.
https://pappadeaux.com/menu/
For more Tex-Mex try Pappasitos. Owned by the same Greek family; go figure.
https://pappasitos.com/home/
Disclaimer: I have no financial or commercial interest in these food chains. Just good food.
Enjoy,
Ed