Iceland

I can't answer your question specificially, but from my very short time in Iceland I gained the impression that public transport was extremely thin outside of the city/airport area.

Thank you for the information!

I don't have Rick's book (I used Lonely Planet on my Iceland trips), so I can't confirm whether you can replicate his itinerary or not. But I would advise you to verify the (negative) assumption about public transportation before giving up. From the main bus station in Reykjavik, one can take buses throughout Iceland.

Here are two websites to check out:
http://www.publictransport.is
https://visitreykjavik.is/city/public-transportation

I own the RS Iceland book. (It’s a good one!) He says there are buses everywhere but they can be quite expensive, esp. for day tours like the South Coast or the Golden Circle. If you are traveling solo the buses might be worth it but for our family of 4 renting a car is way cheaper.

It would be tough and time consuming. We drove and found it easy to do. My sisters took day trips out of Reykjavik and that worked for them. Good luck