Any ideas on how minimise mess, and upset for the cat when she's left at home? It'll only be for overnight, leaving in am and returning next day late pm, neighbour who usually helps out won't be available.
Cat has always refused to have anything to do with litter trays (also goes ballistic and immediately poos everywhere when put in cat carrier so vet visits are traumatic). We gave up trying and she toilets in our garden. She was 2 yrs old when we got her (now 10) and had been a stray used to living outside. No cat flap on account of habit of bringing various wildlife home to play with.