Well, if this were BA - or another airline operating out of their hub - the “reasonable measures” part of the article would come in and it might be possible to expect the airline to find another plane and/or within the compensation period to operate the flight.
Other airlines with smaller fleets would find it more difficult to suddenly magic a plane up at an outstation (as would BA), so the reasonable measures would be much less extensive. It’s why we try to concentrate on BA queries in this thread, because the answer is very much different than it would be with Wizz Air! We broadly know what BA’s resources and capabilities are, but we don’t have that in-depth knowledge to properly advise on other airlines.
That’s why full details are important, but from what you’ve said you’d struggle to claim here - the closure is clearly extraordinary and whoever the airline is it would be difficult for them to suddenly find a spare plane and crew.