I read (from this board) the website of a vet (I don't remember the reference) who says that wet food is OK to be out for 12 hours.
My former cat ate only a can of wet food a day (she also nibbled dry), and I fed her only once a day in the morning, and she ate from the dish throughout the day with no problems.
My current boy eats mainly wet, but he doesn't like his food "stale" and usually will not eat anything that has been on his plate for more than 2 hours, so I have to feed him at least 3 times a day.
If your cat is like my former one, he should be OK with one daily feeding, but if he's like my boy, it would be a problem.
I solved the problem the one time I traveled (he's been with me only 8 months). In addition to a sitter who fed him twice, I had a neighborhood teen who came in to feed him in the afternoons. It was expensive. The next time I travel, I'm considering boarding him, not only because of the feeding issue but mainly because he's an incredibly social cat who needs more stimulation than he gets from a sitter who just feeds and goes.
If your cat is anything like my boy, you might consider boarding.