You have your dad in the right place for treatment. My SIL went there with a 5% chance of survival. That was 10 years ago!
He's definitely in good hands there. It's a 6 hour drive for him, but it's worth it.
Another ray of hope ... he has a friend that had this (stage 4, clear cell type) with a soccer ball sized tumor, spread to brain, lungs, spine, ribs. He's now cancer free. A great bit of encouragement for Dad.