I'm glad I don't have to deal with such dilemmas.  (Bachelor, no children.)  When his wife says he's committed to the soccer game, he's committed.  Case closed.  No ifs, ands, or buts.

If it's any consolation, there are lots of 100-mile runs around the country.  Maybe he can find one not too far away.  Here's a webpage: http://www.run100s.com/ultra.htm

Jim

P.S.   If I'm ever "almost accidentally perfectly trained for a 100-miler", you'll know that h@ll has indeed frozen over.