Yeah, size matters. We are a few feet shorter than you & found ourselves in a private CG to the west of Glacier NP. Apgar again is on our hit list this year too. We provided quite the show squeezing ourselves into a site really not compatible with our size last time there.
The key is arriving Sunday to Thursday & as early as possible. The biggest irritation is finding something like a class B or TC in one of the few long sites.
Boat: 32' 1996 Albin 32+2, single Cummins 315hp
40+ night per year overnighter
2007 Alpenlite 34RLR
2006 Chevy 3500 LT, CC,LB 6.6L Diesel
Ham Radio: VP9KL, IRLP node 7995