You can disable wifi on your router and easily replace it using electric circuit.

I was told that you can’t turn off wifi on your router.

Not true.

You can enter the router manager and switch off its wifi output easily, when you use an ethernet 5 pin to 5 pin connection from your PC or laptop to the router.

Once your wifi is disabled which took me three minutes maximum, you can plug your router into an AV600 Powerline plug (tp-link), using the starter kit, available online, and a pair into a separate plug attaching a device to it.  The two plugs tune in to each other, and at that moment, your electric circuit round your house becomes as good as an ethernet circuit, no drilling or installing required.

If your router is a BT Brightbox 2,

EE have set up the following help pages for this

https://ee.co.uk/help/help-new/phones-and-devices/ee/bright-box-2-wireless-router

the following page describes how to go into change the wireless settings

https://ee.co.uk/help/help-new/phones-and-devices/ee/bright-box-2-wireless-router#connectivity/enable-or-disable-wireless

Piece of cake.  Costs about £50/60 to buy a starter kit or less if you shop around.