Oh and snakes can live off a large meal for a month at a time. I know it sounds cruel and I'm sure you love your pets, but think of it this way: predators are built in a way that they don't have to eat everyday. In our tanks they get easy food dropped right in front of their mouths. In the wild they spend hours or even days and weeks for a single kill. In the tanks they eat more and use less energy getting to the food too. They are built to survive a long time on a single meal. When people leave for long vacations, the killer of fish is usually water conditions, not starvation. That's why I suggest making sure your water is super pristine, and making sure your fish are slightly fat and overfed before leaving. If you like you can even leave a live feeder or two in before you leave if you have time to quarantine them. Those should get them by the first week or two. Then as long as someone can come in and feed them once a week or every two weeks and just a SMALL amount, they'll get by without any harm coming to them.
If you can get someone to change the water, by all means have them fed regularly, but if not, you should be more worried about deteriorating water conditions.