What a wonderful experience we had at the summer home! It's located just about 15 min outside of the main part of Mosfellbaer. This was the perfect base from which to explore the North, West and South of Iceland. We did day trips to the North (Vatsnes Peninsula, Borganes and Akranes, Husafell and Icelandic Goat Center, Snaefellsjokull Peninsula) and South (Reykjanes Peninsula, Reykjavik, Selfoss, Vik) easily, nothing was more than 2.5 - 3 hours away. Golden Circle sites are very convenient.
The home was also very child friendly. We traveled with our 3.5 year old and she was so comfortable in the home. They have a small play house outside, a sandbox and tons of toys and English language TV shows / movies appropriate for small children. We enjoyed the fire place most nights but the space heaters also kept the rooms toasty at night.