I did this route and the only real day of tailwinds I remember was in Utah. I do remember a lot of headwinds as I got into MS, AL, and GA, but I was tired at that point and they probably weren't as bad as I thought.

People who live there could give you better advice than people who've passed through. I've learned a lot more from living in NV for years than I learned from a few days riding across the plains of TX and OK.