It is an immense shame that Llandudno Junction hasn't been sorted out along with Deganwy and up to Llandudno. Not only would some re-modelling help and some higher line speeds at the Junction but equally Llandudno getting an all-day, all-week service. It's amazing the main town is left out on a limb so much.
I'd suggest the frequencies that would make sense would be something like:
1tp2h Holyhead to Cardiff Central (Llanfairpwll, Bangor, Conwy, Llandudno Junction, Abergele & Pensarn, Rhyl, Prestatyn, Flint, Shotton, Chester etc)
1tp2h Holyhead to London Euston (Bangor, Conwy, Llandudno Junction, Colwyn Bay, Rhyl, Prestatyn, Shotton, Chester etc)
1tp2h Holyhead to Llandudno Junction (Valley, Rhosneigr, Ty Croes, Bodorgan, Llanfairpwll, Bangor, Llanfairfechan, Penmaenmawr, Conwy, Llandudno Junction)
1tp2h Llandudno to London Euston (Llandudno Junction, Rhyl, Prestatyn, Flint, Shotton, Chester etc)
1tph Llandudno to Manchester Airport (Llandudno Junction, Abergele & Pensarn, Rhyl, Prestatyn, Flint, Shotton, Chester etc)
1tp2h Llandudno to Blaenau Ffestiniog (Deganwy, Llandudno Junction and all stations)
1tp2h Flint starter to 'somewhere' beyond Chester
No reason, with the new West Coast franchise, not to procure some form of new electric stock to enable the 5 car Voyagers to run through to Llandudno and Holyhead.