On paper at least this was a great matchup. Two big physical very good teams on both sides of the ball. I think under normal conditions this is a one touchdown game and perhaps the New York Giants would've won again, but not in a shutout. Even when the Giants did beat the Redskins in this era, their victories tended to be very close even at Giants Stadium. But this obviously wasn't normal conditions, at least for the Redskins. The Redskins are from Washington, where it doesn't tend to get very cold until January. Winter tends to start in New York/New Jersey in November.
This was a Giants game in Giants weather at Giants Stadium where they were extremely difficult to beat. Very similar to the Green Packers at Lambeau Field when they are good. And now the Seattle Seahawks in Seattle. The Giants got off to a very hot start in this game putting up seventeen points in the first half. With the weather being the way it was and with the Giants defense in 1986, that was more than enough for a shell-shocked Redskins team that weren't prepared or didn't seem to be able to deal with the stadium and the weather.