@RAT 5 - In my experience, once Ryanair has advised you by email that your flight has been cancelled, you'll have a number of clickable options in their email, to either re-book elsewhere (if any suitable alternative routes exist), or a straight refund. Which comes through reasonably speedy. Ryanair (anyone really) cannot levy charges for refunding money for a contracted service that it will not be able to deliver.
So the issue for the passengeres is not getting the full Ryanair money back, but to get alternative flights booked to their destination, which may be far more expensive. If you then already have made non-refundable hotel bookings, car rentals, onward transportation cost timed to connect to the original Ryanair flight etc... that's entirely your risk unles you've insured well.