It ain't gonna happen. Disney wouldn't buy it.
1. You'd need signed releases of every guest & cm at the park that day.
2. Disney wouldn't allow you to say their characters aren't real...(hence,
one could not 'climb into a costume').
3. Disney wants all 'ideas' to come from within their 'imagineering walls'.
I had 2 spectacular ideas for them and I was rejected on both, with
only a 'we don't accept any unsolicited, outside ideas."