Guess, I will offer another option:
Rent car and air B&B's.
With 4 people, a viable option.
We have done that (with my brother and his wire, so 4) all over the world. Last long trip was 2 months in Australia this past summer. 7,500+ KM in rent car. 21 different Air B&B's. We considered two RV's but they would have been more money and less flexibility than a car and 2 bedroom houses/apartments.
We have also done this in Chile, Costa Rica, etc.
While I love RV's, they are not always the best choice for overseas travel.