I expect it depends on a number of factors - how concentrated their customer base is (fully international, some still travelling or mainly UK, mainly not), how much up-front payment to reserve anything from accommodation to access to sites they have lost throughout the crisis, how quickly they reacted to preserve what they could from the wreck, whether they were able to diversify etc.
Also how they tried to anticipate the uncertainty of restart dates, what debt they had to service etc.
John