Posts like this seem to pop up every year around this time. Bored at work I searched the Portland Craigslist for Government Camp housing... there is actually quite a few houses in and around Govy up for rent right now and definitely worth a look. Personally I think camping is the best way to go as long as you time it right, as in after the rains. Plenty of public lands for camping if you know where to look and are wiling to live a decent way off the beaten path. Sounds like you know what you're doing, hoping this can help a few other summer shredders out as well.
And as always, just don't be an asshole... there is nothing more annoying that summer park rats acting like they own the place.