I just got home last night (in Mojave from Indiana, via Utah, I80) it was windy but if your at 74420 you will probably be alright. If I were to run south I would run I40 to Flagstaff, thru Barstow. Just info for next time.
Ran a lot on both 70 and 80. If the weather is good, I had no issue on running 70. Once you get past the big hill, its not that big of a deal. Great scenery on that route.
Never had much reason to run 70. Actively avoid most of it in MD, PA, OH, IN and past that 40 or 80 is better. Never really been on much of it at all in UT or CO. KS, MO, IL it’s okay but rarely down there either
Turn your flashers on if you have to slow down and there’s a chance someone coming up behind could hit you, sure, but once there’s someone behind you going the same speed, turn them off!