Late but here goes.
My driving to work is all motorway bar a stretch of say 7-8 miles of town/urban driving. 150 miles per day.
My average MPG never falls below 43 mpg - Audi A5 2.0TDI Quattro - S Line.
I will admit to being a lets say , enthusiastic driver. 90 when i can on the motorway.
In other words i have no doubt you could beat my effort
I thought i had DPF issues which turned out to be an exhaust sensor (independent specialist found it , main dealer wanted to change DPF). He also told me they can be cleaned rather than replaced. I do motorway miles which means my will not need cleaning for a while however , he said it is quite a simple process. He advised me against a remap/removal.