I thought I'd give a quick report on how this went.
No problems getting the tickets at my local Amtrak office (Homewood, IL), a few weeks ahead, except they've got to have about the most antiquated ticketing system on earth.
The agent made several errors necessitating cancellation and reprinting, and since I was using coupons from the "Chinook Book" (Seattle/Portland area $25 publication like the "Entertainment Book," which saved me $69), everything slowed to a crawl. She had to call some ticketing experts someplace multiple times to get back on track.
It took over an hour.
Anyway, the schedule necessitated overnights in Seattle coming and going, but the train ride was quite nice. It would have been nicer had it not been creeping along much of the way, and I wonder if it's really necessary for the engineer to blow his horn for 2 hours+ on the way north. Needless to say, try to get a rear-car seat if you can.
Customs was a breeze compared to what some colleagues had to go through at YVR. 90 minutes was the norm there, with many enduring much more than that. We cleared customs at the Vancouver station on the way up and on the train southbound in just a few minutes both times.
Vancouver is a beautiful place, with water on both sides and plenty going on, including lots of great Japanese food.
Thanks again to all for suggestions. It sure beat driving, from what I could tell.