Huh. Guess some people are more susceptible to altitude sickness. 6700/feet seems low for that. If you took it easy for the first day or two you should acclimate. You could get a hyperbaric tent and train up! 😹
Yeah, wow, I've never been that susceptible to the altitude.
I spent most of my life around 1,000ft and then went and lived at about 6,000ft, with daily excursions from 8800-10k for 3 months. I felt slow and tired as I got used to the altitude, but never feeling actual ill. Even went up to 14k when I was recovering from leukemia. I was most certainly NOT in peak condition, and did fine.
My vote for your road trip is to keep it to the eastern half of the country. I've done long road trips for riding before, and if you go too far, your trip is at least as much about the road trip itself as it is about the riding. I did an Indiana to Arizona trip a few years ago for the Sedona MTB Fest. I had a limited amount of time (I think about 10 days, IIRC, and if the trip was to be exclusively about riding, it would have been disappointing. I would have had to spend too much time doing marathon driving that the travel part would have been a horrible experience in order to add maybe a day or two of riding. Meh. I ended up planning the road trip a little bit more such that I found interesting things to stop and see/do most days during transit to break up the driving. Did a "Route 66" trip along the way and saw/did a lot of fun little things that made the drive part more enjoyable. Was less tired/frustrated when I arrived in Sedona, and I had a fun time riding (though I could have chosen a better variety of trails to ride, I think).
I know a guy who lives in Arkansas and what I see up there, I think you'd find some great stuff to ride, and while some of it might be very similar to your local goods, I'm pretty sure you'll find enough variety to keep you happy.
Quite a few other areas, too. Lots going on in the Roanoke/Harrisonburg areas in VA. You could roll up the length of the Appalachians, stopping in a couple different areas to ride, and VA could be just one stop. Would break up the driving into more manageable bits. There are some bike parks scattered along the way so you could mix up bike parks with backcountry and some rowdy stuff with more xc stuff.
If I'm wanting to maximize ride time in a farther-flung destination, I've had better results flying out (once even flying with the bikes) to maximize the number of days where I can hit the trails and work in a rest day or two.
