While I've never heard of laws governing unauthorized stayovers, some jurisdictions do have local laws that cover how hotels can evict a guest. Some places require the local police to be involved, which generally means going through the court system. In those places, the guest has power over the hotel because of all the extra hurdles involved in removing the guest.

Even without local laws, hotels are usually pretty restrained when it comes to kicking out a paying guest. I know each hotel in which I worked were cautious on this issue. When a guest refused to leave, we'd change rack rate. Doing that usually covered our costs for relocating (aka walking) the guest that would have had that room.

On top of all of that is the social media factor. No decently-run hotel wants news coverage about displacing a homeless fire victim. So, the OP's question is a reasonable one. I still think it's too soon to know exactly what might happen for a date in the (not-near) future.