As others have said, Alaska pretty much shuts down after Labor Day. Most of the tourist attractions shut down then as the workers all head south. August can be a wet month also. We returned in early Sept and didn't have any trouble with fuel and campgrounds. We did stay at some rest areas overnight when we couldn't find a campground. No big deal. Enjoy your trip but start out in July if you can. We didn't take the ferry so I can't comment on that. We did use our toad a lot to explore. I recommend taking it.
