If you enjoy coding so much that you don't get enough of it at work, contribute to or start an open source project, or create a proprietary software product to sell for your own profit. Don't donate free work to the company that's already paying you a salary for a set amount of effort.
Well, I think the scale of the problems you can takle on your own in an open source project vs. as part of an established game dev studio team is quite different.
Please don't project your own perspective on other's people work/life balance and consider it as the only valid way that things can be.