That's a lot of miles to travel. Remember how big Texas is. You need to Google the route. That's a lot of driving without having a relief driver. I'll worry about you!
I drove from Portland Oregon to Cortez...as the only driver, pulling an 8 X 22 terry camp trailer. I didn't sleep the whole trip and it took me 2 days. :)
I also drove from Cortez to Dallas/Fort Worth by myself. I stopped for a 2 hour nap...woke up to finger prints all over my window...scared the dickens out of me!! I have a hard time sleeping when I'm on a trip now!
Mine said 17 hours 47 minutes from Cortez to Austin. What time is the party? :)