I have a professional pet sitter who comes once a day. We have two cats currently. When the youngest was still pretty young (I think she was about 4months), we left her in a bedroom by herself for a week so that she wouldn't get into any trouble. She probably hated it, but she survived. We paid the pet sitter for an extra long visit each day so that she could spend plenty of time with both of them. A few months after that, we went on another weeklong trip and just went back to our regular routine of having a pet sitter in once a day. Of course, our house is otherwise cat/kitten proofed. They're alone most of the day anyway so leaving them by themselves didn't seem to pose a huge threat. I wish I could afford twice a day visits, but it's usually cost prohibitive.
ETA: Most, but not all, cats do not do well when taken out of their space/routine. Boarding or moving them to somebody else's house for the week, for me, would be the least attractive options for this reason.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher