Per 2008 figures, the MetroWest is to the right of any of Massachusetts 9 Congressional districts by a point or so, but is about 100k short of population. And due to population distribution, such a district may need to add areas Southeast of Worcester (2 districts fit from Worcester directed west!).
The resulting district is 2 points and as many as 4 points to the right of Massachusetts 6th district, depending on choices made.
Bolded the biggest reach you're making here. The success of this strategy would depend entirely on whether or not the 2016 mini-realignment is permanent.
Well, yes, by 2016 figures there is no winnable district. But, if one were to use the 2013 Senate election for the open seat, the proposed district would have strongly voted for Mr. Gomez over Congressman Markey by more than the 7 point margin of the current MA-09 district.
In Massachusetts we require an open seat to be competitive in any district. As stated the metrowest has no incumbent and was cut to smithereens due to having no incumbent.