October should be a great time to be in the Keys. There still could be a storm, but probably not. The weather should be warm, but not the high humidity heat of the summer.
I've never stayed at the Barnacle, although I've heard nice things about it. We've stayed in the surrounding areas many times and love it. Big Pine Key, is very quiet, un-commercialized, compared to other areas of the Keys, but it still has a lot to offer. Looe Key, the best place to snorkel in the Keys is just offshore. Strike Zone Charters, strikezonecharter.com/StrikeZone_Charter_Loo… located in Big Pine, does daily snorkel trips out to Looe Key. There are several nature trails to hike in Big Pine; The Blue Hole is the most popular. You can see tiny Key deer (staying in BPK you'll see plenty; drive carefully!)and other wildlife around the only fresh water lake in the keys. Visit the National wildlife refuge visitor's center in the BPK Winn Dixie shopping center for info. on more trails, etc. in the area. (While you're at the shopping center check out the artist co-op, "Artists in Paradise", lots of great art.)
Big Pine also has great areas to kayak; Big Pine Kayak Adventures, http://www.keyskayaktours.com/ offers great tours, and/or you can rent from him and he's give you a map of "trails" to follow. The owner, Bill Keogh, wrote "The Florida Keys Paddling Guide" a great book that I use every time I plan a new kayak outing in the Keys.
One of my favorite restaurants is in Big Pine, it shouldn't be missed, great food (we love the pizza) and the interior of the restaurant is a great surprise....No Name Pub. http://www.nonamepub.com/
The largest Flea market in the Keys is also in Big Pine, (fun, if you're into that) open Saturdays around 8am. (maybe Sunday, too)
The largest, most beautiful beach in the Keys is just a short drive from BPK; Bahia Honda State Park, is a wonderful place to spend a beach day.
Key West is less than an hours' drive from BPK, the most beautiful stretch of Hwy.1 in the Keys. I can never get tired of that drive! Key West has tons to offer, lots to do and see, and many great restaurants. Check out the Key West forum and review pages on TA for lots of great suggestions.
Marathon, also isn't a bad drive; the old seven mile bridge is a great place to watch the sunset. After watching the sunset, try Castaways' Restaurant (great food, tricky to find) or Key's Fisheries (great seafood, very casual, seat yourself at picnic tables type place), for dinner in Marathon.
