I forgot to mention... In Yellowstone there are lots of little short hikes that are worth doing. Trails seemed to be very uncrowded even on very short hikes. We just asked the rangers what we should be sure to not miss and they hooked us up with some short hikes.

Also I should have mentioned that we were there in early July on a Sunday afternoon plus Monday and Tuesday. The traffic was still heavy but really not a huge problem. I don't know how traffic is for sure at other times, but from what we were told by other riders we met, the weekend is generally to be avoided at least up until late afternoon on Sunday.

Also I won't claim to know more than jamawani who has a lot more local (and general touring) knowledge than I do, but... We were going the opposite direction and had more headwinds than tailwinds. There were definitely both and VERY strong ones at times especially in Wyoming. It seemed to me like it is a crap shoot either direction.