To all those who replied, just a quick note of thanks.
I ended up booking Biz class based on the comments above. A few minutes after checking in at Emeryville, I got a phone call from Amtrak offering an upgrade to the roomette for $26.
On a whim, I went for it. We easily "ate" the cost difference with meals in the dining car. My dad did indeed find the roomette "clautrophopic", but spent much of the time in PPC, which he very much enjoyed.