All the above is correct -- but you should check your ticket and absolutely make sure you are booked on the same train all the way through. I have been offered the chance to book the trip as (east bound 8/28) train #28 to Spokane, and train #8 east of Spokane. Almost nobody would consciously choose to book the trip that way, as it is invariably more expensive, but if it ended up booked that way due to room availability, that would mean a room change in the middle of the night.
I almost never even wake up at Spokane. The whole process is pretty quiet, and they hardly even bump when they combine or separate the trains. For your entertainment, here's a photo from my last trip, where the EB was so late that I got to watch the separation process at Spokane in full daylight. That's the Seattle section leaving the Sightseer Lounge car and Portland section behind. Then they backed another engine in to couple up and take us down the Gorge.
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