I'll be honest, as a sahm, if my h took away iPads or tv, I might end him. Those give me sanity! I do it sometimes, but only if it doesn't hurt me, lol. Otherwise I take away a toy, or dessert. Dessert works well. I never really take anything for more than one day from my 4.5 yo twins. I don't think they can quite get more than that.
Also, I'm really sorry about your dad. It's so hard to parent without terrible things going on. You must be so stressed. Also, 4.5 yo twins are the debil.