Do any schools offer teaching or research assistantships via distance education? I would like to complete an MRes or PhD, but do not live in an area with any schools. I would rather not relocate. I see that many schools offer paid MRes or PhD programs entirely via distance. Do schools sometimes also offer teaching or research assistantships via distance as well?
Graduate study is learning to do research, by working with your advisor and a research group, mostly hand in hand. A small part of that you'll be able to do remotely, but a minority in any case.

Perhaps you can find a job as a TA for some of the online courses, but if I was to select somebody to assist me in this, I'd select somebody I know personally (and even have at hand for coordination or to pull their ears if something goes awry).