In reply to fammer:
I'd be tempted to park in the city centre, evening parking is only a couple of quid and even with the £10 congestion charge it's probably going to cost less than your taxi fare.
There is a council carpark on Fitzwilliam Street, it's barely inside the congestion zone but really easy to get to from Ecclesall Road and avoids most of the anti-car measures that make the city centre a no-go zone for drivers.
Otherwise, train from Hathersage is probably the best option as other than roadside I can't think of any parking on that side of the city.