I doubt that is as easy as it looks given the contract terms - eg you'd need to change the timetables to match the requirement to have units at the Hitachi depots overnight for example - but it does seem an appropriate response if there is no strong return to travel or the issues persist for some time.If demand doesn't strongly return for Intercity Travel the Dft could look at taking a selected number of IET's from all the different franchises for XC
Of course, as with anything else to do with XC, there is already a thread https://www.railforums.co.uk/threads/how-do-you-free-up-800-802-bi-modes.208066 covering the idea of freeing up existing class 80x for XC