If Kamala won, he'd at most get a nice private prison that'd basically a rich people's fancy retirement home, with access to amenities like tweeting from his "truth" social so its basically not different than being not having a prison sentence at all. But most likely he'd not even get prison, but a house-arrest with very relaxed restriction, because the judicial system will make up some excuse saying its impractical to keep a former president in prison citing "safety concerns".