I don't think we'd be looking at the full capacity moving, auld guys like me may want to stay put, so possibly more like 1000 or so. As long as those that want to move know that they need to do it as soon as the half time whistle blows, I think it could be done fairly easily.
I agree, nothing wrong with this idea, however, for games where the opposition bring any more than two or three hundred, I don't see it happening due to segregation issues. That would mean it would be a non-starter if we go up and would be on Saturday because of the trouble previously.