Us as a group? Sure, it's fine short term, but you know when those barrier comes down, the international community will want to know where your father and Granger stand on things, both because of what they did with Voldemort and what happened at the end. On the other hand, I really don't know if anyone will volunteer.
For you and your family? I'm not sure how you will ever savage any sort of relationship with him if you do. I'd say you're paving the way for a split more famous than the one between my brother and my family since it will involved half the people here.