There's an older Brit guy on YT doing the TransAm now from Astoria. He did most of the official route and does mostly camping, but really got peeved at the traffic on poor no-shoulder highways. He did have company for 400 miles or so. After Yellowstone he decided to take hwy 26. He's likely in Iowa by now.
Last year he finished the GDR ok, starting in Canmore.

Everytime I looked at vlogs about that TA route, I think > BORING<. I have ZERO interest in gravel or rail trails.
I rode from motel to motel just fine a day at a time on my own 3,900 mile Can/Am route, none were booked ahead. I was OK with busy traffic and wider shoulders. I did ride some real quiet side roads.