I would suggest that you stay at La Quinta Inn Huntsville, TX - 124 I-45 North. It cost a few dollars more, but is clean and comfortable. Motel6 in Huntsville is a little trashy.
You can book online at Orbitz, Hotels.com, etc.
Just an FYI, there is construction on 45 past Huntsville, somewhere around Centerville. Oh, and the Buckees is right past Huntsville before Centerville. Kind of a big thing here in Texas. You must stop there.
We make the trip to the Dallas area a few times a year.
I hope you enjoy your visit!
Shannon
[h=1][/h]