... So, do I stop setting up dates? Ones that are already set, do I cancel them? Do I stop spending as much time with her? Engaging in nightly conversations?
If she's not actively having an affair, I would not go out of your way to cancel the dates that are already set.
Back off in the future setting up dates, spending time, and nightly conversations. Those are all pursuits. If you do talk to her, listen and validate. Otherwise work on yourself.
