It is not useful for your current situation, but it might be for the future: I think, if there is no way to avoid a split sit, the best thing you could do to avoid drama is:
- Book a cleaner for inbetween the two sits.
- Ask a friend or neighbor to do a personal handover of the flat to the new sitters.
Under these conditions, I could also imagine to do a split sit (as a sitter) 