Do you mean commuting in a car or by public transportation?
Either way, the one resource I cannot get more of in life is time. The more I get on in life the more I protect this resource. And I vow to never give my time to long commutes.
That said, I think that 25 to 30 hours per week is plenty of time to run a side business or consult.
Obviously there are many other factors, but when it comes to my time, it is very near the top of my priorities.