I dont know what Quartzite is. But I have camped on the Keys in winter and summer. The state parks are full, people reserve online the minute they open but there may be some sites reserved for "drive ins". Key West is fabulous, full of young people and excitement especially along the beach drive. I have camped on Key Largo and Grassy Key and didnt need reservations much ahead, called the day before. But then I have a 17' RVan in a pull thru site. Summer on the Keys the water is really warm, my DH got scuba training and did some snorkeling. There are wonderful bicycle trails. It is pricier than other places in Florida. There are festivals at certain times of the year when even the private RV parks are filled so best to check ahead on those.