I work about 45 hours a week, my wife is a full time student, and we have an 18 month old daughter. Having a family is WAY more taxing on my training routine than my job.
Before the baby, it was easy to get 100 mile weeks, but since she was born I have a hard time getting a second run in on weekdays, so now I do about 90 miles a week in mostly pre-work singles. As other people have mentioned, having a kid all of a sudden makes all your free time much more valuable because you have less of it. I almost never have time to roll out, lift weights, ice or anything like that, and little nagging injuries add up way faster than they did while I was college. That being said, having a kid has provided me with way more joy and satisfaction in life than running ever could, so it is absolutely worth it!
I am still improving, but I would absolutely get better if I could cut down my work time to 30-35 hours a week. I'd have time to do all the little things and run an extra 20-30 minutes a day.