The good thing about FR is rather than cancel flights, they try and operate them from other airports, and generally they'll always divert to the nearest airport pretty much all of the time as long as it's open.
Other, especially traditional carriers will just cancel the return flight if the outbound flight gets diverted to another airport or refuse to land anywhere other than a destination that is normally served by the airline.
As stated previously in another thread, it's pretty sensible for Wizz to move and they did the right thing, as pretty much all aircraft running routes from WMI are based there meaning one delay heavily hits the rest of the schedule at WMi as such plane is going to have to operate to a few destinations a day.
With FR with all the flights coming from other bases, they've been able to allow extra crews to pick up the later parts of some shifts rather than the originally scheduled crew that is being heavily delayed.