Amy, How do I leave the door open for my W to return but not actually say anything to her about it?
You decide to.
You must know, though, if you decide that come hell or high water, you are going to stand for your marriage, rest assured that making that decision will be the last simple thing you do. Hell and high water will both come. They'll come often and sometimes they'll even come together before you have time to take a deep breath.
As long as you know that and still decide to stand, it is possible to do it quietly, effectively and with grace. It will take more than you know you have within yourself. You will have to dig deep and eat a lot of crow.
There is plenty of room here at the table.
Make a list. Write down your reasons to stand. You know the basic ones; kids, vows before God, etc.... Now look closer at the very heart of your relationship. There you will find the reasons that will enable you to endure.