If the cat is traumatised it might have fear of being left alone or fear of being in a different environment.
Having animals is a responsibilty. That might mean you have to cancel your holidays.
Whether the above was said with utmost sincerity, or the last line as a gentle joke ; I must confess that after seeing what immense trauma it caused my elderly cat , when I last went away for about ten days ( despite an alleged cat sitter, who must have just changed the feed and litter ) I now am reluctant to leave the chap alone, unless a proper 'live in' can be secured. The evidence suggested that he had fearfully crawled under the duvet, and stayed put for a long time, having defecated over several days - and lost weight.
The task of dealing with the cleaning, was the least I could do - and bringing the poor chap out of his traumatised state, took a very intense / attentive week or two. For me, it was too much to inflict upon an old friend - who of course ( as a rescued from abuse kitten ) sees me as his trusted 'parent'.
Of course it depends on the cat, and the quality of available surrogate care ; but it was a 'Bridge too far' for me to ever repeat without comprehensive measures being left in place. Meanwhile, the old lad nourishes my world more than any holiday might be required to.