I think some people are underestimating the amount of potential player movement this offseason, and how that could benefit the Pats. The Steelers, Chiefs, Raiders, Eagles, Rams, Falcons, Packers, and Saints all have a significant cap crunch heading into the season, and some of those will not be easily correctable. The Pats have the 4th most at $68M; the 5th place team (Bengals) has $23M less to spend.
Watt is probably not coming to NE, but I would not rule out the Pats making a big splash in free agency this offseason.