Where would you like to get to?

There are lots of options, but knowing your final destination would help.

Here are a few ideas in the meantime:

Catch the Piccadilly Line to Kings Cross.Take the train from St Pancras to Chesterfield (Midland Mainline). You can obtain good fares if you book in advance. Taxi or bus (bus will probably take a VERY long time!) from Chesterfield onwards.

Alternatively, you could look at the National Express coach routes. This would take longer but would be cheaper. I’m not well-versed in this, but I am sure that it is possible.

Third option would be to hire a car and drive up.

My choice would be the train.