What field are you interested in (and what degree level)?
One of the dirty little secrets of online education is that almost no one finishes their program. Seriously, completion rates are less than 5%. We human beings need to interact with other human beings in order to challenge and push ourselves and learn, and online courses are often the worst version of packaged lecture ever.
If you're just looking for the credential (like you need a degree to get a raise or a job you want), then you can try to skate with an online program. Otherwise, they are very weak, with a lot of charlatans and fakes out there trying to take your money. If you feel that because of your schedule some online work would be really helpful, find a regular university and take some classes in an online or partially online format. Down the road that may change with improving technology, and it's starting to change a bit in terms of some computer science / learning to code things. Right now, though, that's the lay of the land.
Talk to your local University. If you are pursuing a graduate degree at a larger research university, tuition funding (and a job!) are quite possibly available depending on your field, and there are lots of other programs to support non-traditional/returning students.
MBAs can be a reasonable investment, though beware of the programs that are targeted primarily at corporate ladder-climbers. Very expensive, and the questionable ethics will drive you a bit crazy.
In the MBA world there is a lot by way of part-time "Executive MBA" programs and some online options. The professional schools that can do it find that's very lucrative. As you know, I'm in a "pure" academic science discipline.
Lots of need in the sustainable area, but lots of competition (and a lot of quacks, too).
I'd be inclined to look at U. Washington or Western Washington, but I'm way too far from my field to give any real advice I'm afraid. There are programs on sustainability that are taught out of colleges of Natural Resources or Colleges of Sciences as well, but they don't get you the business component. Still worth looking into, because they are more likely to get you a paid graduate assistantship which pays all your tuition, and which you could make work alongside your interpreter work. MBA programs generally don't have graduate assistantships, so you have to pay tuition.
It's pretty well known in the field. MOOC completion rates are even lower.
I think right now it's safe to say that while a lot of institutions are playing with the online thing (we certainly are), we really haven't yet figured out how to do it well.
I thnk MIT offered some free robotics courses which at the end of the course you could get credit by paying a fee for the test
I'm not sure it's credit that one's actually paying for (although some courses are good for Continuing Education Credits), but actual proof of passing that you can show an employer. At least that's what I'm aware of for a lot of the MOOC university courses.
Our (U.S.) government has started to look at online universities that are targeting former military who are looking to further their education. Those under scrutiny are shamming the online students with creative financing that ends up substantially padding the online school's bottom line and leaving the applicants holding a considerable bill and little education. And the dropout rates are deplorable. Just a word of warning to be careful.....
I like the idea of MOOCs, especially from top universities like Stanford, Columbia, Yale, Harvard, Purdue, blah blah... there's a definite trend here. You'll only get a certificate on completion, so it's really just for personal advancement, which (as an old man near end-of-career) is all I want, but it's still a bit of documented proof to enthuse someone willing to hire me. Kind of like university extension courses, which I did benefit from decades ago. (I took a Berkeley course in data communications, long before the internet was born.)
I should add... several of my courses have been online, provided by where I'm going to school. I don't think college transcripts even specify whether the course taken was online or not, but in any case, there's no distinction between online and in-class courses in terms of credit towards a certificate or (AA/AS) degree. I'm often able to learn more online and make better grades because it's at my own pace, including the internet at my fingertips to consult other sources any moment I want other or more in depth details for a topic.