Go across Canada after September and see how many campgrounds are open. Walmarts, Casinos, Travel centres are your friends. 45 days across the country to Manhattan and all but 3 dry camping.
The other thing is, when dead heading, why bother with a campground. What service could they possibly provide that I would need. I have 100 gallons of water on board, solar, batteries, satellite, generator if needed. Seems frivolous to have these things and then pay to buy them from someone else. Any security issue we have ever had were in a campground. Not in a Casino, travel centre or Walmart. Generally speaking I find campgrounds inconvenient for overnight stays. Parking lots are like big pull through sites. Not always easy to find in a campground. Many campgrounds are unstaffed after hours. Picking up supplies involves getting parked, unhooking, driving downtown to a Walmart and buying supplies and then driving back to the campground...in a strange town. To each his own. I have no problem with folks staying in campgrounds if that's where they are comfortable, or maybe their unit is not equipped well for dry camping. I am always amused by those that seem concerned with where I sleep.