django-survey | simple django framework for creating and conducting surveys | Form library

I'm trying to build two abstract classes called SurveyQuestionBase and SurveyResponseBase that will serve as templates to quickly define new concrete Models for implementing specific surveys on our website. The issue I am having is in enforcing that the SurveyResponseBase model, when made concrete, should define a ForeignKey to a concrete model of SurveyQuestionBase.

Django does not allow us to define ForeignKeys to abstract classes so I cannot, for instance, do this: question = models.ForeignKey(SurveyQuestionBase) Neither can I have it as None or app_label.ModelName for similar reasons.

One hacky fix is to create a new concrete model SurveyQuestionConcrete and make the ForeignKey point to this: question = models.ForeignKey(concrete_model), combined with validation to ensure this model is replaced.

Is there a cleaner way to achieve the same thing? All I need to do is ensure that when someone defines a concrete model from SurveyResponseBase they include a ForeignKey to a concrete model defined from SurveyQuestionBase

Here's the full code: