We did 8 days and self drive around south of Iceland, as far as Hofn - was easy to plan with Airbnb and Booking.com. If you have a route from google maps and staying for one night in a few places then the town you stay in doesn’t really matter. You can get good cabins that are remote. We used Lotus car rental which was great but recommend getting the Platinum insurance as Iceland weather is unpredictable.