My wife and I spent 17 days in Iceland last September, 2 weeks of that time driving around the island in a camper van. It was
very crowded with tourists, especially along the south coast. Basically after about 9 in the morning, parking was at a premium at any known attraction, (i.e. wait, along with dozens of others for someone to leave). That was pretty much the same story everywhere along the Ring Road. If you saw a good shot along the road, well there was already several photographers there with their tripods set up up. After a few days we abandoned the south coast to the crowds and headed north.
The weather was marginal most of the time, heavy overcast and rain/drizzle. We did get to enjoy one sunny day at Vatnajökull National Park, where I beat the crowds with a wide angle at Svartifoss (see
here).
Once you are off the Ring Road, there are a lot less tourists. In the north, the exception was Dettifoss which was crowded on both sides. If you are camping, Vatnajökull National Park was a pleasant place to stay and explore the Ásbyrgi canyon. Husavík has a fairly decent local whale museum with some good exhibits. The main reason for most people to stop at Akureyri would be to buy groceries at the Bónus store. Lake Myvatn is moderately interesting, for say a day but again the crowds detract from the natural beauty of the area.
One interesting campsite we found was in the Vaglaskógarvegur National Forest Reserve, it's south of the Ring Road and east of Akureyri. Forests in Iceland??? Yes, it's a natural birch forest with experimental plantings of various conifers. We just about had the entire place to ourselves, just 1 other camper and they were locals.
We spent a few days in the southern part of the Northwest Fjords, and while there were certainly other tourists, it wasn't crowded. I think this is where you would have to go to find a bit of what Iceland used to be like, that and maybe the East Fjords. However, it was often very windy there, windy enough that it limited how much driving we could do on some days (our insurance wasn't valid if wind speeds were over 15m/s).