Seattle-Tacoma Airport

Hi all, 

I am planning on arriving at SeaTac on July 1st with my Bike Friday, I was planning on doing one of two things.  Ask a nearby Warmshower host if I oculd leave the case for my bike while on my 10 day ride around  through the northern part of Metro area to the Canada border. Shuttle to their house and put my bike together and hit the trail.  Or use my case in the trailer mode and put the bike together at the airport, get on the train, go up to UW on the train then head north.  I am leaning toward the second option. My question is can the case in the trailer mode go on the train attached to the bike or does it need to be detached?

Thanks in advance,

Michell