Welcome to Vodafone Community
I applaud your post and your efforts I'm sure mods can look into it for you but would you not look at repeaters/boosters/extenders (all mean teh same really) to send the WiFi all around your house?
Might be a cheap way to achieve what you want without spooking the folks.
Whats your current speeds like? You can check at the link below. Test wired and wireless connections: