Have you looked at NGOs/non-profits?* Many of them are very small and cannot afford full time coders/developers/support. They might not pay a lot, but if you gather a bunch of clients together you can easily start making quite a bit. They usually have comparatively simple requirements, but are very underserved because they cannot pay as much.

I would say, though, that NGOs/non-profits can have very interesting employees, to put it kindly. They are usually very stressed, underpaid, and overworked, but also very committed to the cause. For those reasons, I'd recommend approaching them only on a contract basis.

Another option is Higher-ed. I've seen some absolute coast jobs in higher-ed related to archives and databases. You can easily be only working essentially part-time hours for full-time (modest) pay.

* By no means should you only think "charities" --- many NGOs/non-profits are arts and culture/legal related as well, for example.