Hi Chris - I'm very new to this but my conclusion is lots of very short videos for maximum flexibility for the students. My training is for people in sales roles and they're a bit notorious for short attention spans!
I'm currently scripting three courses each of which will initially be a similar length to your 2 hours. I'm aiming for 2 minutes per typical lesson, longer only when absolutely required. One difficulty with my approach is that it might take 15 seconds at the beginning and end of each video to connect to preceding and subsequent lesson.
Like you, I'll be very interested in any other comments.