Is it possible to provide local geolocation data?
I'm not sure of a software program or change to your router that can do this. However, your web browser does have emulation options that can fake the GPS data to give you the desired results.
If you're using Google Chrome, you can press F12 to bring up an Developer window. Click on the blue icon on the top right of the developer frame. Then click on the Emulation tab. In the Sensors option, you can Enable Geolocation Coordinates.
