Deb,
I have no experience in paper mache on that large a scale; however, I will
suggest plaster bandage as a means to get a large, figurative sculpture
off the ground. It is strong,east to use, durable and dries quickly.
Key is your wire and wooden armature. make certain you have an unwobbling
base upon which to build this thing.
I love your idea. Maybe I will try it too!
Best,
Robin