I ran plus 100 for years while working. At first I was a teacher and had no family responsibilities. By 1994, I was into a very demanding teacher/principal role working 50+ hours a week. Surprisingly, I ran my best race during this time (11th at IAAF WC marathon).
I would get in an easy run in the morning before school (5 miles) and then a run in the evening. I made the most of my weekends with a hard fartlek on Saturday and a long run on Sunday. Long runs were done at a decent clip (marathon pace +30"/mile) on soft surfaces. Mondays were very easy 5 miles and a massage. Tuesdays were hard sessions. I used a heart rate monitor for easy runs. Often I was more mentally fatigued after work and the monitor showed me when I was slacking off.
Trick was staying healthy. I found that extra protein (red meat) helped. Having the summers off helped prepare for big championships.
I stepped away from teaching for a few years and took on easier contract work. Having more time to train didn't really correlate into better perdormances.
When I went back to full time work, I ran to commute. Every weekend I would pick up my dirty work clothes and drop off clothes for the next week. Logistically it was a big deal, but by then I had a wife and kids and this was the best way to minimize the impact on my family. Weekends were HARD!