I am glad that your wife (and you) have maintained civility in front of the girls. There is not a lot about what has happened that I am able to take comfort in, but the one thing I can say is that my H and I try and show mutual respect for one another in front of the children. I see him holding his tongue when he is upset at me (and about to go into bully mode) about something. He would not have held back before BD - he would just have let rip. So, if nothing else, I respect him and am thankful for this small 180. He does it for the kids and not for me. But I am thankful anyway.
9 - 10 days: now that is something to look forward to. And she will not be there to play around with your emotions so it should be great. I have a lot of divorced friends and the norm here is the dad sees the kids every second weekend and one night a week. I think this is unfair on both the mum and the dad - a weekend is not real life. An overnight is not real life. Weekend dad's get to play super dad and don't experience the day to day monotony of life with kids. It's parental tourism. You only get to scratch the surface. But a week, that sounds awesome.
The email you got sounds a lot like the many exchanges I have - though mine are daily. Friendly, cordial but non committal. A part of me knows this is the way it has to be, but a part of me hates it too. How dare you tell me to keep warm !!! But I know this anger is me and not him. She too is trying to keep the peace. But I know you know this. And yes, it is good practice for future relationships.
The routine will kick in once the childcare is a little more settled. Plus, it's January. Most people, even those not going through this cr@p don't get back to normal until mid Feb.
I too hope the nightmare ends soon (for both of us). I think yours will end sooner than mine though.