Cflaguy

I never really thought about trying it so I can't really tell ya. I imagine they can go long periods if need be. I'm sure it happens in the wild. But it doesn't mean it is good for them. Columbus brought Galapagos and Aldabran tortoises to the Queen. They went months w/o water. Some lived another 60+ years, some died of kidney problems fairly quickly.
One might try to leave a big bowl of water. But I change mine every 2-3 days so that wouldn't work.
They do have dog water purifiers. They keep the water flowing constantly and have filters. May not be a bad option if you're going away. However, they are relatively small and a baby sitter would have to refill it.
Sorry, I'm rambling.