Well, it's not a C5 event, but there will be the All-Chevy show coming up soon.
I may try to do a 2nd cruise later this summer independent of the PNWCC. We had 8 2010 Camaros show up for the Winthrop cruise...and it was a blast. May try to do something that heads either out to 101, or maybe around Ranier/Mt. St Helens.
None of this would be officially a C5 get together though...just kind of informal