I will be taking a similar trip in a couple of months, starting in SW Louisiana, just passing around the DFW area on the way, I am also going to try to bypass much of the mess that is Denver. In my case I will be driving the motorhome up, and my wife will be flying up to meet me in Laramie, then flying home once we are done with Yellowstone leaving me to make the big drive back by myself. I made a similar drive a couple of years ago helping an old friend move back to Montana. Our route then, and likely my route for this summer will go up 287 through Whicita Falls, Amarillo, and on through to Limon CO, probably then up to Brush CO and across through Greeley up to Wellington and back to 287 into Laramie, WY. I drove this road from Fort Collins, CO to Laramie CO last year in a van, and it was overall a good road with fairly light traffic. Just be aware that 287 from just past Amarillo through Limon CO consists of vast expanses of nothing, you have 350+ miles where you don't drive through a single town of over 8,000 people, and most towns are in the 1,000-2,000 range even these are few and far between, Limon itself only has a Population of 1,880.