That said, I wouldn't recommend leaving your job to go to school full time either. Why not take night classes and get that degree over time? I think that, at least right now, in classroom is a superior experience to online, so I would probably go for some place that you can actually sit in a classroom. Even if it's just at a community college to start. I got my BS in Electrical Engineering, and didn't really like my curriculum. So, after I graduated and moved out to Boston, I found out that Tufts University offered classes that residents could audit cheaply. I took a few programming courses to plug holes left by my degree, and a philosophy course with Dan Dennett (because it was Dan Dennett and I had to).
Some of my favorite courses at university were not programming courses. Among my favorite courses were: Free Will, Literature, Nietzsche, Data Structures, Game Development, Differential Equations and Quantum Mechanics. You would miss out on most of those unless you are actively seeking them out.
There are also some soft-skills that come along with education, namely, being able to communicate well. This is one of the more important things when it comes to landing a job, at least for making it past the first level of filters. I've seen some awful cover letters and resumes, it helps a lot to be able to write well, and state things clearly.
Also, I'm not sure what you think the lifestyle of Silicon Valley is like, but for me, it's just a lot of hard work. Don't get me wrong, I love it here, but it's not particularly glamorous. Perhaps the biggest draw, well two biggest draws, would be that, first, you'll never (assuming we don't have another tech bubble burst on us) have trouble finding a job here, if you're a decent programmer. And second, that you'll regularly run into other programmers everywhere. If you're living some place where people look at you funny when you tell them that you build computer programs for a living, and would rather live in a place where people generally have a clue as to what you're talking about, this is a good place for that. Also, you probably won't have trouble finding a job here.