Sounds like a nice trip.
Commenting only on the Texas legs: Both I-40 and I-10/I-20 have higher speed limits (80mph IIRC) on long segments, so if traffic allows, you can make very good time. Either way takes you pass a large wind farm or two, which I find inordinately fascinating.
I-40 offers only a few glimpses of old US 66 as Bus I-40 thru a couple of small towns. Cadillac Ranch is right on the access road of I-40, although you can't quite see from the freeway. US 287 is four-lane for most all of the way, has significant truck traffic and it's not uncommon to get stuck behind a truck bottleneck where one truck passes another at a 2mph differential. I don't remember any traffic lights on that section of US 287 but there might still be some at-grade intersections. US 380 has a lot of traffic & traffic lights but is being upgraded, so has a lot of construction right now, might want to assess that just before you travel. (Depending on where you're going in Dallas, consider TX 114 to I-35E or TX 114 to TX 121 to I-635 to I-35E as alts if needed.)
I-10 coming east of El Paso has a long area signed (and enforced) keep right except to pass, which led to much more wear and roughness on the right lane. Kind of annoying to ride washboard right next to some pretty smooth-looking pavement. Mostly two-lane-in-each-direction segments and a fair amount of truck traffic but easier to pass than on US 287 (at least in my own completely random sampling). Extant remnants of US 80 remain along I-10 & I-20. If you come this way, I would carefully plan your way thru Ft. Worth (a major city with traffic problems in its own right) on the way to Dallas. (Depending on where in Dallas you're going, could also stay on I-20 to I-35E or could take I-35W to US 121 to TX 183 to I-35E.)
Have a nice trip.