So, as of today's phone conversation with my vet, I am at the fork in the road with two difficult choices.
One fork is to have Rugby euthanized now, before he slips deeper into discomfort and suffers further.
The other direction is to see if a woman my vet and I know and trust is comfortable having Rugby sent to her farm to live on pasture and see if living in the field on grass without the confines of stall and a stalled horses diet will save him. We will send her enough Banamine to keep him comfortable but will take no more measures medically to prolong this. We don't know if he will survive the trip upstate to her place. We don't know if she will feel comfortable with it and agree to a potentially terminal case to be in her care. And I completely understand if she says no.
If she doesn't agree to it then I will not let him suffer any more.