London to Nottingham fall 2023

easy train from Gatwick 3 times an hour (Thameslink is the train company) to St Pancras International station on the northern edge of central London. Thameslink is 2 flights underground so two escalators up to the main level or a lift/elevator, and the station is full to bursting with shops and restaurants and take-aways. East Midlands Railway connects London with Nottingham. EMR trains leave from the upper level so directly above Thameslink but 3 flights up. There are stairs, escalators and a lift up from the main floor to the EMR waiting area, and more food outlets up there.

Sounds complicated, actually quite easy.

From Heathrow it is a little more complicated. Just over an hour on a Piccadilly line tube train straight through from Heathrow stops at Kings Cross St Pancras tube stop (not for long so be ready - the previous stop is Russell Square) after going into and through central London, There are stairs, escalators, and a sequence of lifts which get you up and into St Pancras International - then follow instructions above.

Or from Heathrow, you can take Heathrow Express to Paddington station and then taxi or change to the Circle or Hammersmith and City Underground trains to Kings Cross St Pancras (the previous stop is Euston Square) - then follow instructions above.

Or yet another choice, from Heathrow you can take the new Elizabeth Line (purple is their colour) to Farringdon (previous stop is Tottenham Court Road) where you can change to Thameslink one stop to St Pancras International, or Circle line or Hammersmith and City Line or Metropolitan Line one stop back to Kings Cross St Pancras - then follow instructions above.

The last, making use of the Elizabeth Line may wind up slightly faster, but if you don't mind a tube train which stops quite a lot the Piccadilly line version is simplest.

That's why I like Gatwick...

Thanks, Nigel, for the very detailed directions.
Very thorough and clear. Much appreciated!