Hi,
I think you should have worded your post "what are your DP's ex wife's plans for you for the summer holidays?" 
Well, as yet, I don't know.
In theory, it should be that we only have "normal" access, despite DP working 7am til 9pm and only coming home for meals. So, every other Friday afternoon to Monday morning and a day in the week too.
In reality it all depends on ex wife and her current situation with her love life. I suspect love life is not going too well, hence her being a bit clingy with the kids at the moment, (which suits me), so we shall see. We certainly won't have the priviledge of knowing what's going on until the very last minute anyway.
We have also had the news that she is going to need a fairly major operation soon and this will possibly mean we have the kids full time for 6 - 12 weeks! Of course, she won't bother to inform us until the last minute - we heard this from ex wifes Mother.
It's just a case of waiting and see what happens and hoping that DP will be supportive of me and DS and our wishes too.