How long is a WW able to live this delusional fantasy without feeling anything?
Potentially forever. From what I have witnessed a lot of WSs, (both husbands and wives!) usually have a good bit of Narcissistic personality disorder going on. Unless they get serious therapy for that likely it will never go away, and they will continue to chase a delusional fantasy without feeling anything until they do get help.
So if you are trying to wait that out I think it is a fool's game. You are better off doing the work you need to do on yourself and moving forward healthy and happy. It can be done but you have to stop worrying about her at all, stop worrying about what she has or hasn't posted on FB or what she still has up, and just focus on yourself and the kids.
Drh, you've got this. Upward and onward!
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018