Fantasy rail alert!
8tph from KX plus all the FCC services? That will kill journey times, as everything will have to queue to cross the Welwyn viaduct.
Also, how long are you looking at for turn around time at Kings Cross? With only 9 mainline platforms, space will be at a premium.
It's not fantasy, it's the needed level of service for lots of place-particuarly Middlesbrough & Hull-the bare minimum.
Yes, this would require work-I think a 20 year Franchise should be prepared to include a second Welwyn Viaduct and quadrupling where possible in their plans.
Let's not forget that lots of the paths for this are already there-the hourly Lincoln service is an extension of the current FCC 'fast' to peterborough, the hourly Aberdeen service (which only goes to Leeds, so is definitely pathable) takes over XC north of Newcastle and provides the hourly long-form Edinburgh-Aberdeen express the east coast needs.
The 2-hourly Lincoln service via Newark is certainly viable when you include stops in the south. Also, given the movement of many FCC services onto Thameslink in the next few years, more platform space at LKX will be freed up.
This isn't crazy, this is what we should be aiming for-if not more. Currently ICWC fits 8 departures every hour from Euston, with more to come in extra trains to Liverpool, and 'semi fasts' to Crewe. That should be possible on the east coast.
In an ideal world I'd like to see Lincoln (via Newark), Middlesbrough, Hull & Cleethorpes all get hourly services through to LKX, plus extending of the current FCC peterborough 'semi fasts' to Lincoln via Spalding, & Doncaster (as per the LM model to Crewe).