From Nov - March I use my "b" ride 12 miles each way, about 50-55 minutes
From Apr-Oct I use my "a" ride, 17 miles in about 55 minutes, 13 miles back about 45 mins

As far as the time question goes, I figure it take about a half hour of "family" time per day longer than driving. If I drove I would still need to find an hour or more to go to the gym, run etc etc, so biking is for me and my family a win win situation.

good luck