My commute is 21.7 miles each way and I have two young kids (5 and 7 years old). I get up at 5am, leave around 5:30, and arrive at work around 7am. I leave work around 4:15pm and I'm back home around 6pm (the way home has more climbing).

My commute is hilly (3000 ft of elevation gain for the round trip), and it only takes me about 1.5 hours each way. If your commute is relatively flat, 1:15 each way should be doable. Then again, not everyone wants to spend 2-3 hours/day on a bike. If that's too much, perhaps multi-modal commuting is for you.