Hiya! I'm by no means a professional, just a fellow applicant, but from what I know you're doing the right thing by getting all the references you can. Two should usually be fine, since those are the people who did nevertheless teach you in one way or another. You don't have to have met them as long as they still have enough experience with you to be able to vouch for your skills, work ethic and whatnot. I believe it would be best to mention that they were only your teachers under the conditions of distance learning, maybe they could at least talk about how you were able to make the best of your circumstances or how you're an efficient communicator. So yeah, I think you should be fine, best of luck!