I'm voting against the basement for two reasons. The first is what Corri told you: it will make her a victim (again) and play right into her hand.
The other is more basic: there's no impetus to work on things when you're not together. I see a move to the basement ending up with the two of you living seperate lives under the same roof. That will relieve some of the stress from both of you, which is good. But it will also probably lead to both of you feeling better, at least temporarily, and wondering if living apart is so much better, why not really live apart.
My advice, FWIW, is to hang in there. It may be painful for you, but if you believe the things that Corri said in the proposed email to Mrs. HD, you're going to have to suck it up and endure the pain. You need to show her that you're really trying, not just taking the easy way out. Your actions need to say that it may be hard, but that you truely believe that the result is worth the effort.
