There are several sites out there that do a slightly better job than Google, at the cost of convenience and speed. Strava uses your own history over the route, if you've taken it, and
http://cycle.travel can compensate for hills if you haven't. But it's not like taking your car and wondering how long it will take your car to drive to a destination 800 km away. The app Osmand also works well if you don't have a data plan for local trips.