I just graduated from OMSCS and have four young kids and a full time job. It took me four years and I made full use of my employer’s generous continuing ed program (50 days/year, introduced about a year after I started) which kept after-hours work to a manageable level. I had to pass on a few good courses due to predicted workload, but made it through a good number of the harder/more rewarding ones and am very happy to have done it. I do not think I would have stuck with it if I was working 40 hours/week and doing the program entirely on my own time.