Good detailed report and sorry to say you are definately not the first to ski that route although we missed out la masse
I have been fortunate enough to do 3 weeks this season in the 3V two in Meribel and last week in VT, Have been to VT about 15 weeks now and always thought what a great location, last year stayed in Meribel for the first time and then two weeks this year and have to agree with you middle valley every time, I know the area very well and for four days managed to ski around 50km a day and never skied the same run twice leading a group of 6 which I thought was a great achievement unfortunatley no one else noticed, up until last year had never gone into Meribel had always skied straight through Mottaret over to Courchevel huge mistake great runs from top of Olympic down to Raffort are wonderful and quiet conditions permitting
Have already booked same chalet for next christmas in Meribel