Putting a train in storage is still likely to save some money compared to keeping it running. Plus if demand does pick up then it is likely going to be cheaper having to buy new trains again because the old ones were scrapped.
However a lot of newer trains are designed with maintenance costs considered, as such you may find that it's cheaper to scrap trains and replace them with new, as long as the scrapped trains were likely to have reached end of life within the next 10 years anyway.
Although I do agree that we should consider what happens in 2021, maybe 2022 before making significant changes.
There's no point implementing cuts of half of train services only to find that they are all full and standing 3 months later, especially if you've made a lot of staff redundant in the process.
I would, however, expect that staffing costs would likely be where there's going to be cuts, probably more cuts to station ticket offices. To do that you might need to bring in a national smart card system so that people could buy online and at ticket machines much more easily.
Present smart card to reader "good morning The Ham, how can I help you today:
Extend season ticket duration
Purchase a recent ticket
New journey from this station or the extent of your season ticket
Pay for parking
Print pre-purchased tickets"
That would allow most journeys to be done with the touch of 3 buttons, however for many they would install an app on their phone and use that.
If you then had a roll out of interface ticket machines (able to call for assistance) the staff that you did have could be better utilised.
Yes you'd still need ticket offices but you could probably reduce the numbers at the small stations and the overall number of staff at the bigger stations.
