Hi guys,
I too have had "frozen face" on occasion. Mine always only lasted for a few minutes (thankfully). It used to happen regularly when I was teaching and talking a lot (as I regularly do). I used to make a fish face (suck in my cheeks and chew them a bit to get feeling back) so often that my kids started making the same face back to me. It was pretty cute actually. I'm lucky that I never had any noticible drooping other than in my eyes.

Hope you have a great day!
~Kathy