Population wise and urban area wise, it's miniscule.
Yep. For comparison, there are 53 incorporated cities in the United States that have a greater population than all of Iceland (372,520). If you expand it to metropolitan areas, it's 147.
Edit to expand: 37 of the 50 United States have a greater land area than Iceland too. So Iceland is pretty small in both regards.
My city in Poland that's not the biggest one has still more population that the entire Iceland.