oh 1st...this post just made me cringe because it reminds me of when my ex moved out. And now you are reading advice from other sites and want to give that a chance. You are basically helping her find a new life without you. You both want to keep that connection? While being in an open relationship?
Another stander once wrote to me something like "she is about to hit rock bottom but you are throwing a mattress under her". That is exactly what you are doing by messaging with her, having dinners etc etc. I know this because I did the same and I deeply regret it today.
My ex fought as hard as she could to have me in her life but all that meant was that she wants to dip her toes in the scary waters out there but she also wants to the comfort of knowing you are there in case she doesn't find the happiness she's searching for. She wants you to be her plan B, nothing else.
Me: 38 Stbxw: 35 No kids Mini bd: February 6, 2019 ONS confirmed Sept 7, 2019 Told her to move out: September 8, 2019 W moved out: September 28, 2019 Divorce filed by me: September 23, 2019