Seems a Ditto,

There is a practical route going down the cost, to Reedsport, take the Smith River Road back to Eugene,
you can pickup Amtrak there to get back to Seattle .

Talgo Commute train still Running ? wont need to box the bike for that one. runs more often than
the Coast starlight , (at about 16:00 'ish')

Why?.
Southbound Rail Route turns east and crosses the Cascades there, and then goes south to K Falls From there ,
so its no longer a useful Return option.