"well I would rather you stay here and work on the M with me, but most of all I want you to be happy and if you feel that leaving is what will make you happy then I support your decision and will help in whatever way I can."
Hmmm. Would the above be okay to say to her before she moves out? That is actually kinda how I feel. The first part seems like it would be backsliding on the distancing a bit. My gut tells me she would appreciate hearing it though.
I understand your concern about the first part possibly being a backslide, but I think in this case it's OK because basically you're saying you're setting your own desires aside to allow her the freedom to make the choice. She already knows you want her to stay and you want to repair the marriage, so you're not really putting additional pressure on (in fact you're taking the pressure off).
By the way, the structure of this statement comes from Dobson's "Love Must Be Tough" which is a good read if you have the time.