Keep in mind that the Metrodome itself is really big. If you wanted to organize a march, there's plenty of distance to be covered just going from a tailgate around the stadium and even around the concourse inside the stadium before getting to a seating area. That all depends - during the previous Thunder games at the dome (at least the non-Beckman ones), the back lot that's actually adjacent to the stadium was open for tailgating, and given the size of the crowds it wasn't hard to get in there and get a spot.
That's not to say I'm against a march, be it from Brits, or from elsewhere, or just from the tailgate out of the parking lot and down to the front plaza and into the stadium or something. But I think it can certainly be coordinated to do both a march and a tailgate, one way or another.
She thinks she missed the train to Mars. She's out back counting Stars.