There actually is no way to predict it since it depends too much on the house itself. The actual distance the radio signals go is about the same on almost all quality routers. Even old 802.11n routers transmit at the same legal power. It is the transmit power that determines the distance. Now there is some difference in the actual speed because newer router cram more data into the signal but that is too hard to combine the ideas of how much speed you get at certain distances. The main problem with cramming more data into a signal is interference from neighbors has more chance to damage this transmission.
Be careful about chasing big numbers. It is mostly marketing hype to get those who just figure bigger is better...