Icy roads are certainly within the possibility of things at this time of year. There have already been some winter storms to impact I-10 this winter, but you'd have to check the forecast to see what things looking like as you get closer to your departure date.

Ballpark estimate for fuel is going to be about $400.

BTW, Donna suggested Van Horn as a stopping point for night 2, but I think you'll need to get farther east than that. Its more than 600 miles from there to Houston, which would make for a long last day.