Well, I started the wonderland at Longmire heading north on Friday at 3pm when it was still pretty soggy from earlier rain. I turned back after 15mi for a net round trip of 30 mi. and about 9500 ft elevation gain. I was okay until I got past S. Puyallup to where the trail was overgrown and got completely drenched from wet shrubbery. My boots were full of water and I anticipated many more miles of the shrubery and broke mentally. The total effort was about equivalent to a spring trial I did comprising 3 consecutive laps on Mt. Si but I took a couple of hours longer moving time (~10hrs). In addition, I gave my bivy gear a test about 5mi from the car on the return at midnight and found it wanting. After an unsuccessful 2hrs of horizontal shaking time, I moseyed back to the car to nap before the drive home.
Pick a dry week - October is a little late in the year --> September next year
Wear running shoes (I ended up going with boots)
Splurge a little weight on bivy gear (I took about 8oz)
Pick a little slightly slower pace on climbs to keep the cumulative fatigue down
Rest a little every few hours rather than going until you start stumbling.
I avoided stopping at all to keep from getting cold
--> take an insulated shell jacket to bivy in and and to keep you warm during rest stops
Train a little more, concentrating on stretching hips and hamstrings
I'm a little dissapointed but I'm super psyched to try again next year.