[villagetinker]

I have found that locating your primary Wi-Fi unit in a central location provides very good coverage. Our house (without the additional room) sounds similar to yours, and with the Wi-Fi located on top of a grandfather clock in the living room we have great coverage in the entire house, garage, lanai, and birdcage. This is for both 2.4 and 5 gig signals. If you cannot do the central location, I would look into reviews of these types of products as i have seen some good ones and some bad ones. Also, make sure you consider what you are using the Wi-Fi for as this may greatly effect the use of a mesh system.