If you don’t want to do the haul between Cascade Locks and White Pass, hitch into Trout Lake. It’s a nice town and very hiker friendly. For me it was probably the easiest hitch I had on the whole trail. At White Pass, if necessary you can also hitch into Packwood.
Also in regards to the bailout possibility. I’d recommend bailing at Rainy Pass, not Hart. Rainy is on a
pretty major road with a big parking area and popular trailhead. Hart Pass is not much more than a forest service road, very little traffic. This is a just in case sort of thing, of course.
The Summit Inn held a package for me in '05 and didn’t charge me anything but it might be because I got a room there as well, or because I flirted with the cute girl at the front desk. I’d like to think it was the latter but given the way I smelled at the time, probably not.
I personally believe that you’d be set with Yogi’s PCT Handbook for town info and the PCT data book for trail info.
Hope this helps. Washington is beautiful, have a great hike!
ducky