Just wanted to add that you can tell your driver you need a ride back. It's very likely that the driver will wait for you and take you back to WDW. We took a taxi in June to Holy Family Church in Orlando. The driver waited in the parking lot for us. We would have gone to Mary, Queen of the Universe Shrine had we known that Holy Family was so far away. We liked the idea of a Saturday evening 5pm Mass so we went there. Very nice Church, but too far from WDW to make it convenient.
The taxi drivers are really hurting because of the Disney Magical Express so they will go out of their way to accommodate you.