I do plan to go DARK while at my fathers. I can call each of my boys on their own cell phones, never a need to call the house at all.
I would suggest proactively sending him a short e-mail stating what I said above, almost word-for-word. It lets him know that you are seeking advice, and "not sure what you're going to do," and the wording is designed to throw him off-center.
You should also ask him to respect your privacy at this time, and NOT badger him, and since you've set up a way for the boys to be able to reach you, there should be no reason for him to.
Short, business-like, civil. Don't convey "wounded" or "hurt" or -- god forbid -- anything mushy.
In my opinion, he needs to begin to feel that he may have lost you.
