My personal guess is no. The peace provisions would mean that enough of Virginia is snipped off to make Washington safe for the Union, and it would be a point of pride that they would not move the capital in the face of a foreign threat.



That being said, I would imagine provisions would be made to ensure that the United States government can function in a time of war without the fear of harassment by a foreign power. I'd expect that there would be a place where "back up" institutions would be readied and probably most important information would be stored outside of Washington lest it fall into enemy hands. Philadelphia or New York would be my bets where this would be set up.