You don't have to give up hope to detach. You give up letting everything she does or doesn't do (or seems to do or seems not to do) not get to you so much and not cause you to react toward her. You still care. You still have hope. But it is tempered by the reality that even if she decides to come back it will take lots of work and that your mutual decision to continue to stay M is the outcome of that process.
You're right that she has not taken steps to move this along. This may or may not mean anything, but at a minimum it means there is time, and that is your ally. That should give you hope even if she is not going slow because deep down she still thinks she might reconsider.
I'd also ask how much of your marriage were you having substance abuse issues? She may be giving you the time to see if the changes are for real. It will take a long time for her to trust that, and she is not going to give you hope if this is part of her agenda. Think about it as the scientist not wanting to interfere with the agenda because they want to know what the true results will be. You are doing well on this path, so just keep it up and focus on what you need to do. She will be more likely to respond positively if she sees you really focused on changing yourself for yourself rather suspecting by your attention on her of just doing it to win her back.
While you can't help marking dates and time in, they are totally arbitrary and unimportant. You don't know what it will take in terms of time for her to start changing her mind, so the dates really, really don't matter and will only make you frustrated if you dwell on them.
Just keep up the good work you have been doing.
Me: 50 W:43 S6, S3 M: 12 yrs. T: 17 M is bad & Not happy Bomb Mar '14 S 5 Feb '15 D Bomb 13 Apr '15 (but "no hurry") DB Coach May '15 Wants proceed on D Aug '15 Starting 1-on-1 negotiations Sept '15