Always glad ato see someone from MA on this board. I don't fish out your way but would suggest that the best place to fish is probably the Swift river in Belchertown. It is a slow river that is the tailwater for the Quabin. Its flow is very consistent and the water comes out from the bottom of the reservoir so its temperature is always somwhat moderated. It has a population of small midges so fishing can be done with # 22 - 26 flies. It is not a pocket water river so you may have an easier time fishing it.
Don't get frustrated as winter time means less activity and therefore less success. Hope to see you on the water.
jed