I would only have concerns for helping your wife learn TTATT. If you can help her wake up you would probably find attempting a fade much easier.
I can imagine how difficult it would be having a wife that still believes. I didn't know at first how my wife would respond and I was stressing about how to approach the subject. I was pretty lucky that she trusted my concerns were genuine and came to the same conclusion as me. It still sucks though, we have young children and our parents are in the org but we want out.
I know how frustrating and thought consuming the whole situation is. Learning TTATT and then the turmoil that comes afterward can be one of the hardest things someone ever goes through. Take it slow, and look after your own health. Many have been able to help their partners wake up by being patient.