Now that we have Crossrail there are quite a few ways of doing this|:
Jubilee to West Hampstead then Thameslink (TFL recommended, suggests 43 minutes)
Northern to Tottenham Road, Elizabeth to Farringdon then Thameslink (TFL suggests 47 minutes)
Or change at KX or walk to Blackfriars and pick up Thameslink there.
I did the Tottenham Court Road one last week. Fairly easy interchanges despite being at the back of the train so loads of platform walking. Going via W Hampstead is out of station interchange but don't think that would take me TFL's suggested 9 minutes. Changing at KX St Pancras may be loads of walking.
Gut feeling is there is not a lot in it and TCR/Farringdon is the best.
Jubilee to West Hampstead then Thameslink (TFL recommended, suggests 43 minutes)
Northern to Tottenham Road, Elizabeth to Farringdon then Thameslink (TFL suggests 47 minutes)
Or change at KX or walk to Blackfriars and pick up Thameslink there.
I did the Tottenham Court Road one last week. Fairly easy interchanges despite being at the back of the train so loads of platform walking. Going via W Hampstead is out of station interchange but don't think that would take me TFL's suggested 9 minutes. Changing at KX St Pancras may be loads of walking.
Gut feeling is there is not a lot in it and TCR/Farringdon is the best.