I agree that this is probably realistic but still incredibly difficult to call 'humane'.
Here's a definition from a quick web search:
Characterized by kindness, mercy, or compassion.
Would you say that an individual who has the choice not to kill an animal and does it anyway is doing a 'humane' thing? Does it make difference where that killing happens?
I think ethical meat can only truly exist in theory (though with cell culture meat I suspect that that will change).
Anyway, I just wanted to say 17 years is a long time. Thanks for walking the talk. Not many people do.