No competent programmer I know has to work 40 hours a week to have their needs met. The best ones charge rates would allow them to have their needs met working <10 hours a week.
If wasn't supporting a whole raft of people who aren't my kids I could get by on 10 hours a week. Most of these people will be self sufficient in the fall. Then we will see I can get fewer hours.
Charge hourly, produce good work(actually work those hours you charge) and spend enough time learning to stay proficient in your niche of the craft. This recipe won't make you a millionaire quickly, and it won't get you a house in the bay area, but it has given me great financial freedom in the Midwest.
The few engineers who care to engage in the negotiations which yield their true market value end up making several times that of the average. Yes, some of them are exceptional engineers, but some are not, and the only real distinction is being able to find and negotiate optimal market rates for their work.
Last year I had a consulting gig in a Europe based company, with offices next to a big airport. As summer was slow anyway I'd work 30h weeks (invoicing four 7.5 hour work days) Tuesday - Thursday, and spend the other 4 days at a beach in Ibiza, Bulgaria or Cape Verde (with occasional remote login to take care of emergencies).