My PG daughter has done this twice. As a five year old she retired from kindergarten in January and returned as a second grader the following fall. She stayed for third, but took this year off as a fourth grader and will return for 5th in the fall. She has a fabulous school and has experienced some really outstanding teachers, but she learns FAST and mostly on her own. She likes school, makes friends easily, but is also an introvert and needs a lot of solo time and time to create. All day, every day, school (even a great one) can feel like interference for her.
I think her time away has offered her unparalleled learning experiences and has also kept the "idea"of school fresh and attractive for her. She is radically advanced and in some warped way I actually thought the time away would diminish that somewhat. In fact the opposite has happened. But the main point is, it's definitely a viable option, especially if your school is on board and can be supportive.
