Anacostia Park across the river from the Nats Stadium, but I think the very ideal place would be Oxon Hill Farms. It is directly across 495 from the National Harbor with its World Class Hotels (Gaylord and the new casino), less than a river mile from Nats stadium and its in PG County.
3 things come to mind when thinking of this location...National Harbor, Nats stadium and Redskins' new stadium all on the DC, MD VA border.
Snyder would be able to work with PG County to save from paying off the stadium lease. There is still 15 years left on that lease I believe.
With the Gaylord across the highway and Olde Town Alexandria across the river, it would be a very attractive location for the Super Bowl.
It's an ideal location for the MD, DC and VA fans. They would have 295 north, 495 north and 495 south to get people out of the stadium.