I kind of figured this was common but I think our school is a little excessive in the all or nothing. They have no provision for if another child fills your spot. And I know that the school is young and still developing so the chance of a waiting list in the elementary side is unlikely but they don't even account for it.
We aren't expecting to move DD but we also know that DD isn't really being challenged anymore. When she started there she had the buffer of having to learn all the curriculum in Spanish but now it isn't much of a buffer which forces us to look at what she is learning. Of course, DD is still the type that doesn't like to show her abilities and doesn't ask for harder work (could be the age) so she waits for the class to start doing things together and then she is at the top of the class. IE. reading, addition, subtraction.
Yep, we have a lot to consider. Thanks for the responses.