5 Months unpaid leave takes us through a very quiet winter to the start of the summer season. The thing protecting pilots at the moment is the fleet/seat mix and the long lead times and capacity bottlenecks for training vs the short term nature of the slot alleviations. Imagine a world where they find themselves unable to fly/keep the Heathrow slots.
Internal rumours about the summer 21 plan going through the system are quietly positive.
My personal view is some kind of flexible % cap for % pay is a likely future step for flight crew if reductions are necessary.