We made the trip 3 years ago from NJ. We went out I-78 to I-81 and worked our way along the Interstates to New Orleans. Spent three or four days there and then headed out on I-10. Other than some rough road at the La/Tx border and the feeling that it took forever to get across Tx, that route worked out well for us.
We were in a no hookups campground in Quartzite which got us use of the dumpstation. If I go back, I'll just boondock. We're normally full hookups people, but that just doesn't happen much in Q.