Boston is still one of the best spots to be, South Shore MA an even better spot. As others have noted, it's likely going to come down to nowcasting mesoscale features to determine whether this is a 12-18" event in eastern areas or if the more outrageous high end totals will be in the cards. If you're going to chase in Eastern MA you're going to get a good snowstorm regardless, but something historic isn't locked in at all IMO.