Driving from Florida to Albuquerque NM in Sept.

We take 10 to beyond Slidell and then (I think) 59 to Shreveport to pick up 20.

You gotte cross Louisiana some where. and 59 is better than 20.

This trip we are doing the major sightseeing at the ABQ Balloon Fesival and then the parks in Utah. So passing on Memphis, Oklahoma City, NOLA, etc.

Have to be home by mid Nov, so might do the Fl panhandle beaches on the way home

We have done that trip quite a few times. I'd just get on I-10 and head west to Ft Stockton TX. Take US 285 north there to avoid El Paso. Then either follow 285 up to I-40 or Albuquerque. Or you can go west at Roswell on US 380 to I-25. Good roads all the way with the exception of Louisiana (as always). This runs you right past Carlsbad Caverns if you haven't visited them before.

US 285 north of Roswell gets a little lonely so fuel up when you can and eat in Roswell. We did this trip in reverse in July on the way home this year.

Depends on what you want to see. You will only hit Atlanta if you go north far enough to Interstate 20. I have done most of the highways out there but not with a TT or as an RV'er. Lots to see between your departure and destination.

I recommend going one way and coming back another if you have the time.