We do it every year for the family vacation. I typically change the water for everyone, and go on vacation for a week. I change the water when I get home, and offer a meal, since it has usually been 10 days since the last meal. Actually the lack of interaction typically causes at least a few if not upwards of 15 snakes that have been fasting for a while to eat and begin eating again. I do have someone that comes and checks the A/C while we are gone to make sure that the ambient temps don't get too hot or cold from an A/C malfunction or power outage, but other than that, they do fine.
Lastly, we only clean our cages once per week. Therefore, often times a snake will deficate an hour after cleaning, and they do fine living with it until next week. Sometimes theyt may get some on their skin and need a bit of a wash, but otherwise they are just fine.