First, have you set your alarm to go off and if you did, why didn't you hear it? Check your notification settings before going to bed. And set the app to override do not disturb and silence modes.
In my experience, I will wake up if my BG falls in that window between low and too low to treat it myself. But everyone I different so don't take my say so that you will. But it looks like it was about 3.5 at the lowest. Which is low, but I don't think coma-inducing low.
My top tip is to set the alarm to go off at 4.3 or so. Then you can monitor it and take action if it continues to drop and you might be able to turn it around before the hypo hits you.
Oh, and another thing - could it have been a compression low? It looks like it was down for about two hours, till maybe you started waking up.