Peak,
In these cases, we recommend an 80/20 50 mile plan and “level down.” If you would normally get a Level 2 50-mile plan, get a Level 1 instead.
Frankly, I can’t fully endorse this solution. I just don’t know how this will work. I’ve made the recommendation many times for 60, 65, 70K races, but no one has ever come back to say “you suck!” or “it worked great!” I think that the best option might be to find a competitor’s dedicated 60K plan and adjust the intensity to 80/20 ratios. It would be disingenuous of me to claim that my “level down” idea would be superior.
David