I'm with Airbubba. There is an approved procedure to do engine out, non-revenue ferry of the 747 - i.e. 3 engine ferry (the procedure is in the AFM) - but I've never heard of anything equivalent for the 777 (or any commercial twin).
If it's non-revenue and the crew agrees why can't you get approval?
Don't they do test flights with an engine out on takeoff?