Qatar Airways unveiling probably the most generous cancellation/change policy (and potentially hackable if you find the right deal and plan your booking right?).
From their Travel with confidence page:
Whether you have booked or are planning to book for travel up to 31 December 2020, you can rely on us for the best travel solutions.
As always, we are here when you need us.
Keep your ticket and use it when you are ready with our extended ticket validity, now valid for 2 years from the date of ticket issuance for greater flexibility.
Call any of our offices or contact centres to extend your ticket validity.
You can change your travel date or destination free of charge, as often as you need, for travel until 31 December 2020. You can change your origin to another city within the same country or any other destination we fly to within a 5,000 mile radius of your original destination.
Call any of our offices or contact centres to rebook.
Swap your ticket for Qmiles and redeem them towards reward flights, extra baggage or cabin upgrades when the time is right. For every 1 USD, you will earn 100 Qmiles that are valid for at least three years, so you can have the flexibility to choose how, when and for whom to redeem them. Not a member? Simply join before you submit your request.
Exchange for future travel
You can exchange your ticket for a future travel voucher with 10% additional value. Vouchers are now valid for two years from the date of voucher issuance.
Rest assured, we will refund your ticket to the original form of payment if your flight gets cancelled.
More T&Cs on the page linked, or in comments below