Sounds awful OP, hopefully if you ask they can find you another site though it may be a bit of a trek depending on where you are and availability - this weekend has been really busy for many hotels (as my spouse said, it's like everyone is trying to squeeze in their holidays before they're canceled).
The 'contingency plan' works when a couple are out, not the whole team, and is often reception staff and if the site has one around a manager picking up the pieces and many places don't have spares of those going around either. The other contingency plans involves having other sites nearby that might be able to pick up some of the slack.
they could move available staff around a few hotels to provide a skeleton changeover day cleaning only.
Knowing several people who work for PI and similar - they're pretty much already still working at skeleton crew levels.
Even now where my spouse works, reception staff still are doing some housekeeping duties to try to keep housekeeping hours down. It's not uncommon for afternoon and night reception staff to have to make up rooms housekeeping didn't (which leaves the desk empty which has repeatedly caused issues).
People are leaving hospitality work in droves, hours have been cut, and many places are running the bare minimum required to function to keep costs down which mean every bump pushes hotels to the edge. There have also been hotels which have either been on the edge or had to close purely because the outsourced laundry wasn't being delivered properly for weeks.
I agree it's a ridiculous business model and its going to crash much wider sooner rather than later and there should be more consumers can do to push businesses to change, but the idea that they can just shift the non-existent extra staff around who are already burning out to fix this is even more ridiculous.