Current commute is 11 miles each way. I would go up to 15 without any problem. I wondered what would happen if I had a 20 mile commute. I think I'd do it, but not 5 days a week, not because I couldn't, but coz it would take up too much of my time.

I know one guy who commute 20 miles each way, 3 days a week, lives in a beautiful part of Italy/Swiss border.