Make ahead? Could I make this the night before I want to serve it? Would I keep the cheeses ands sauce separate until ready to serve?

Yes, you definitely can make this cheese spread the night before (I see in the recipe instructions that you can store the cheese in the fridge overnight) and yes, keep the sauce separate until ready to serve. Give the sauce a good stir and bring both the cheese and the sauce to room temperature before serving. ;o)