A lot of industries, especially travel & hospitality have been badly impacted by Corona and have been forced to pause operations.
Guess what? People do still search and discover your site through various channels. They might not convert now but you will still have a chance to convert them in future if you have a lead capture in place.
Have a banner that leads to a form on all important landing pages including home page that receive the most visits and let users know that you will be opening up operations in the near future and if they want to be notified when they restart.
Throw in an enticing deal such as "Get a 25% discount exclusively on any package". Currently if you are not doing anything about this, your leads will go waste. With this strategy, you will already have a list of leads to pursue when you do restart operations.