This may be too late, but I just say your post this morning. It's been a few months since I traveled that route, but I don't remember Hwy 75 being terrible. Certainly not as bad as Hwy 69! There was some construction on the Indian Nations Turnpike just north of McAlester, OK (I think) where they are removing a McDonald's that caused a little bit of a slow-down. Just remember that the Indian Nations Turnpike is a toll road until right before the interchange with I-40 at Henryetta. I hope you see this in time for it to help.
Robert, Teri, Buddy, & Bitsy
2014 Infinity 3610RL 5th Wheel
2007 Chevy 2500HD Classic Duramax/Allison