Thanks to all who have commented. No bad dreams this weekend that I can recall. JJ, I really liked the simultaneous approach you mentioned, toward futures with W and without W. I suppose I have been doing that subconsciously anyway for about the past 6 months.
Lillie: the interpretation you mention sounds a bit closer to the one my friend had. I am not sure whose is more close to the "truth," but I am clearly going through some conflict.

This weekend, W just seemed rather distant. No fights, no overt anger, just a baseline level of distance. When she came to bed last night, I was reading and she started talking to me about a case she has. I did not put the book down, but when she asked questions, I provided simple answers. A couple of her questions were pretty technical in nature, and outside my area of expertise with the law. I suggested some people to ask, but basically said that I had no idea what the answers were. After I put down the book, turned off the light and went to bed, she was still talking about her job. I suppose I could have looked at this as an opportunity to engage her in conversation and maybe close the distance gap which had been evident all weekend. Instead, I decided that I didn't really care about closing it--especially not at bedtime on Sunday night. I finally told her that I needed to get to sleep, and she stopped talking.

I suppose part of my new-ish comfort level with ending her talking came from my refusal to play along with her 11th-hour and feeble attempt to get close after a weekend of distance. I suspect that she tries to be distant during the weekend because it is the one time during the week when I actually might try to initiate intimacy. I just don't feel like playing that game anymore.

My plan is to tell her fairly soon (either during our vacation to Wisconsin or soon after) that I intend to move out of the bedroom if things don't improve. By "things don't improve" I mean if she doesn't agree to a schedule. I will live downstairs for about a month, and then, I'm considering moving out of the house altogether and into my mom's house, which would greatly complicate matters for everyone, but I think it has to be the next logical step. I have to show her how serious I am about this. At the best of times, we're mere roommates. At times like this weekend, I feel even less close than that.

As for custody matters, it is entirely possible that she could try to move out of the state, taking DD3 with her. This would hurt a lot of people, including DD3's half brothers and sister. I don't think she'd do that, as her business is doing well, and, when she is calm and sane, she realizes the importance of DD3's relationship with her father and the rest of the family. There are certainly some worst-case scenarios, but what happens, happens. I'm still quite committed to making the marriage work. It is still goal number one. I just feel better having some contingency plans in place.

Hairdog