My pick would be I-70 to Limon CO, then 287 all the way down to the west side of the DFW metroplex, probably Decatur TX, then go on a side road excursion for about an hour to Weatherford TX. I did this route in a moving truck going the other way to Montana a couple of years ago helping an old friend with vision issues move. Then get on I-20 east, this skirts the south side of the DFW metroplex so there is only 10-20 miles of intense urban interstate traffic and about 75 miles of urban sprawl (think of the drive from Denver to Fort Collins) . All other routes I know of around the DFW metroplex have longer delays and more stop and go traffic. At Shreveport LA take I-49 down to I-10, this is a mostly empty stretch of interstate which was built about 25 years ago, the only city of any size is Alexandria LA, otherwise is is mostly farm county or wooded , not even many exits with gas stations. Then it is I-10 to Baton Rouge, I-12 to the Mississippi state line to bypass New Orleans and back on I-10 again Across to Pensacola and across 98 to Destin.