I know quoting mpg for anything bit your own personal circumstance can be misleading, but I'm going to do it anyway, seeing as you asked!
Over the last three and half years (129 fills) my calculated mpg has been 38.0; the trip computer over that time has averaged a reading of 39.3mpg. Yes, I really am sad enough to keep it all on an spreadsheet.
[Bear in mind this of for my previous generation Proceed; broadly similar weights and CdA, but mine will have slightly less economical mapping you'd imagine (Euro5 against Euro6d), but you will benefit from the 7th gear on the DCT which is much longer than my top 6th. The DCT will in theory be will more economical in most casual driving].
As with everything, it depends on your typical driving. I do boring motorway commutes for most of my mileage, and I tend to just stick the cruise control on and go with the flow, overtaking nothing but HGVs. A jaunt up the M1 the other week resulted in a new record for my Proceed, recorded 48.0mpg over 208 miles (photographic evidence available!), so it can be done.