Jerry wants to get his WiFi signal out to his backyard garage, about 300 feet away. Leo says that WiFi is meant to travel 150 feet or less. You'll probably need a directional wifi transmitter/receiver. Check out radiolabs.com to learn more.
But to your backyard patio, a mesh router would work. Leo recommends the NetGear Orbi, and you can get an outdoor island receiver, and that could possibly get to your garage.
Can Jerry get his own and save on the rental fee from his ISP? Leo says absolutely. Save the money: it'll pay for itself in a year.