My house is 210 years old - wood lathe and plaster walls. I have a router in the living room with wi-fi. I get good reception upstairs but the signal doesn't pass through the walls to the kitchen. It is intermittent at best. Other than running ethernet cables to the kitchen (a mammoth job), what is the best way to extend the wi-fi signal. I've read about wi-fi extenders and powerline extenders, but not sure which might be best for a house like this.