I made it across the Idaho panhandle in a single day. The terrain was mostly easy, rolling hills. There were a few areas with no shoulder and guard rails with high traffic, but more of the roads were low enough traffic shoulders were not needed.
Crossing the Pend Oreille River, there were suddenly a ton of pedestrians. I noticed a large number of kayaks crossing the river and then, upon closer inspection, swimmers. It turned out there was a swimming race. This was rather inconvenient for me because pedestrians were blocking the path for a mile or so. Because my bike is so wide with bags, it was not helpful to get off and I settled on rolling really slowly through the area.
I also stopped at a local ice cream shop while waiting out a downpour.
I camped at Big Eddy Campground, a small forest service site. A large group had parked their cars at a different site than they were actually occupying and I camped between their cars. There are only 5 sites, so everything else was full.