Maybe try Memquisit Lodge, their just east of 64 and may let you park for the 3 days.
Plenty of empty islands up in West Bay too and I've often seen tents on them.
https://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&sqi=2&ved=0CCIQFjAA&url=http%3A%2F%2Fwww.memquisitlodge.net%2F&ei=qg2SU_jVLYeOyATMq4DQAQ&usg=AFQjCNGSBtQDrB8MkFPhKPcQfp05MIyJ4w&bvm=bv.68445247,d.aWw