1st you must recognize that if your house have wifi dead spot, it is inevitable your need to use repeater or extender.
These are technologies exist to overcome the wifi short comings.
2nd Have a open mind. No one router solution will solve your home wireless problem.
Go to the internet and review what people are doing to get their problem solved rather than whine down here.
Look at this youtube, how old uncle fix his home wifi issue. Which is much bigger than a 5 room. All it takes is action speak louder than words.
1.
Review Open Mesh WiFi for a Large House
2. Look at this blog, even auntie also do something to make sure her wifi issue is fixed.
The Solution for Wifi Coverage Issue in the New Homes Layout
3. Lastly how I fix the wifi issue for a 3 storey terrace ?
Let me share my experience, the dlink-850l given by starhub can only cover 1st & 2nd floor and 3rd floor room nearest the router. The master bedroom at the 3rd floor totally cannot receive any wifi signal.
Since the owner is not keen to lay a cable from the main router to the to the secondary router , but is ok to lay a cable from the daughter room to the master bed room, all I need is get a Prolink 3001A, run it as a repeater extender, connect a cable from the Prolink to the PC in the master bed room. Now the owner can surf and work happily. On top of that the Prolink can provide wireless internet access for the owner to connect his mobile/tablet to it.
So do more review and get a better idea how you can plan your own solution .
While knowledge is Power
Power without action is Zero. Back to origin point.
Hope you can see where is a actual problem now.
Note : The 868L router is a high end router that is capable to cover a 2 story house.