The service I would propose would be 4tph in total for north TPE, 2 Liv-Vic-wherever and 2 Pic-wherever (there are 4 "north TPE" destinations - Newcastle, Redcar, Scarborough and 'Ull - so one to each, no strong view on which way round), nothing to Ringway and the Ordsall Chord served by Northern extending services that presently terminate at Vic from the east around to Oxford Road bay or Ringway if they must. If you want Picc specifically change at York/Leeds or use the tram. Cleethorpes as it is using double 185s. Local stopping services back to Northern where they belong. Bin the Edinburgh off.
Would that be operable using just the 80x and double 185s?
(I'm ignoring the WCML because it's a bit separate and I don't see as strong a reason to bin the 397s, but if they got that bad there is no shortage of either available or soon-available 110mph EMUs such as 350/2s or the ex-GA Electrostars - or if Avanti go for a permanent reduction in service could they serve it using their 7-car 80x or shortened Pendolinos?)
I think in reality the smartest thing is a standard half-hourly path (xx:24 and xx:54 I believe eastbound out of Liverpool, I think it's xx:02 and xx:34 into Liverpool), on the Liverpool <> York axis, only stopping between Manchester and Leeds at Huddersfield. That's 11 diagrams for 802 between Liverpool and Edinburgh (if you want to do that sort of thing, think long term I suppose); and then 6 diagrams for a Liverpool to Hull if you then use the other path. That's a good use of 17 units out of 19.
Add to that a half-hourly Piccadilly to York path (Stalybridge, Huddersfield, Dewsbury, Leeds, Garforth) extending to Redcar and Scarborough and you can encourage split and attach of the Redcar portion to give 11 units used; and Scarborough is 12 units (possibly 10 or 11 if you split / attach on Platform whatever it is up around the corner). That gives a remainder of around about 29 units.
12 units for Piccadilly to Cleethorpes (all doubles), and in theory 4 diagrams if you were smart and did Manchester - Castleford stopping via Huddersfield (6 units if you double two high peak services each way); and 2 diagrams for Huddersfield to Leeds. Instead of doubling them, you leave them as they are and just stop the odd other peak service at high peak at Mirfield, Batley and Morley (mixed) on the other services.
So far we've only got to 42 units. If you then finish with a half-hourly Airport to Stalybridge via Ordsall (good units for it) and a half-hourly Airport to Rochdale (might as well, no?) to give a standard, quarter-hourly Metro path over the Ordsall chord and you're now sitting on the last 9 units used. Obviously you need a maintenance spare, but you could sub-lease three 195s to mix into that lot; or sub-lease 6 units the other way to Northern.
Anyway, that's me...