I'm only two hours south of Amarillo. But you'll miss me by about a week and 5000 miles.
Can I offer some advice? I don't know if you've ever made that drive through Louisiana,
but if you take this route, , you'll avoid the Atchafalaya Basin bridge on I-10 which has
been known to be shut down at times for wrecks, plus it's a speed trap. You'll cut off some miles, avoid Lafayette, and
it's a nice drive.
Also, if I may, instead of trying to go to Amarillo through Decatur from Dallas, I would stay on I-20 all the way through Abilene
to Roscoe and then take 84 to Lubbock and I-25 to get to Amarillo. It's more miles but it's interstate most of the way
and may save you time in the end.
I don't mean to be presumptuous, but I used to make this drive twice a month... (in one day)... when I was working in the gulf.