This was the key ride to determine if I could do this trip - Lolo Pass. Turns out, as most events in life, the anxiety exceeded the difficulty, and although it was difficult it was rideable. It appears that most passes on major hiways run 5% to 7% grade maximum. While Lolo was 4 miles of climbing, I took a few breaks and easily arrived at the rest stop at the top.
The downhill was a thrill until it dropped to about 1.5% at the bottom and the afternoon headwinds came up.