I commuted 5 miles each way for 8 years. It was good in the morning and allowed for as long as a trip as I felt like on the way home. I had rural and quiet town options of up to 30 miles. It was a distance I could cope with in poor weather.

For the last three years I have commuted 15 miles each way. It requires getting up earlier than I like and but in general is a near perfect distance in good weather. I gave up winter (sub 15F and snow covered roads) when my commute reached this distance.