I don't think he would have stayed home if he'd been selected. It isn't a competitive award, it honors one's body of work. He might have gotten a laugh out of it, but I bet the would have attended.
Given that he did not attend the Golden Globes to receive the Cecil B. DeMille Award—which also honors one's body of work—I have no idea why you would "bet" on his attendance. After an entire career, I doubt that his convictions would suddenly waver.