Closest legal good spot is up Town Hall Rd in Bartlett but I think that road has been closed since Irene. Many do successfully park overnight at the base of Cathedral but you might get woken at 3am if someone feels like patrolling there. I'm not sure if First Bridge is signed with no overnight parking... you could probably park in the climber's lot over at Whitehorse, keep a low profile, and not get noticed, also the parking lot outside the Echo Lake State Park gate... behind Flatbread (pull the curtains and who knows you're in there) lots of places I would attempt to park overnight but again they probably are not legal and you might end up with more than a warning...
