Coming in from Grimsby so either:
3 hours by train to Kings Cross and then 45 mins by tube or whatever to get to the HEX.
Or however long it takes to get to the Docklands. Easy enough getting there for the London marathon Expo a couple of years ago.
3 hours by train to Man or 2h10ish by car and then a 1hr flight to LHR.
Plus the waiting around etc....
Suppose by flying to LHR my baggage would be checked in for the next flight so I wouldn't be lumbered with it?