Thinking about having families come to church at assigned times to record parts of the Christmas story... then somehow meld it all together and post it online.
I like the idea.
What if you broke the Advent story into three or four parts, one per week, and had two or more families sign-up for each week to POST their own "1 minute" video version of that part of the story on your church's Facebook page, or send it to you for posting on your church website? That way you'd get variety and more people involved and no need to edit or compile it yourself.
You provide the script/scriptures and parameters, and let them decide how and where to creatively modify and record it. That way they could do it on their own time with their own resources. Assign the first week to people who have some creative ideas so that others get inspired.