Last week I asked if anyone had done this. Today I baked off the frozen muffin batter before I came to work. I'm happy to report, it works just fine! I had pre-scooped the batter into each paper lined muffin tin. Wrapped it well with Sarah Wrap and put that in another freezer bag.
Baking time took maybe 7-10 minutes than the original 20 minutes. I just pop the frozen muffin tin and all into the pre-heated oven.
My co-worker will be eating freshly baked muffin for this mornings meeting.