No, No, No you must realise by now that Southern Fail will not be prepared for the heat and the rails will expand, causing speed restrictions on all lines, which will result in cancellations as crews will be out of position, and also to avoid penalties for late running trains.
Also forecasted to be a heatwave at the weekend, which if accurate all the roads into the city will be busy and there will be gridlock within the city, so probably best to look to arrive at the Amex at least 5 hours before kick off if you are going.