I'm doing this now, but don't have a wife or kids to worry about. It's still HARD. Pacing only solves the burnout problem, but fails to solve the satisfaction problem. Only working 15 to 20 hours each week leaves a lot of gaps where we simply lose track of our short term goals and spend a lot of time re-orienting ourselves. When we actually have a productive day, it creates frustrating contrast to the unproductive ones. You constantly think "if only we had another 25 hours each week, we'd be so much further along".