We have put together a short survey to capture your feedback in terms of what BT can do when you experience home Wi-Fi issues. We would appreciate it if you could take a couple of minutes to complete a short survey. Read more from here, Fix my home Wi-Fi
Take a look at the following thread:
Our TV expert @Dan-O confirms that the guest networks Guest Wi-Fi bandwidth is set at 20%.
I noticed you mentioned that your local football club has speed issues. Do they have a residential BT Broadband service or a BT Business Broadband service? I only ask as I may be able to point you in the right direction for support.