Highly doubt anyone here knows much through personal experience of the Big Foot Trail(BFT). I was attracted to the route as a tree hugger(Horticulturalist) and for its remoteness. There is a significant portion of forest road walking from what I gather. I've hiked some of it and did research on it recently as part of a longer hike - Oregon Coast Tr, which I'm thru-hiking now, currently near Blandon going SOBO, Sage Clegg's Japhy Ryder Route -
http://sageclegg.com/expeditions/japhy-ryder-route/ , and the Cali Coastal Tr. I'd want to be DONE with the BFT by late Oct/early Nov! as the route follows some remote little used trails that absolutely do experience snowpack. I'd have all the Wilderness Area maps(your 15 days will include) and BFT Guidebook the BFT SITE RECS TOO!
http://www.bigfoottrail.org/route/guidebook/
Have fun. Seems you're still not solid on your route. Wish you well.