I used to have an entire front porch loaded with plants. They'd all make it 1 week between watering (I'd adjust soil mix if they didn't). But for longer time away while on vacation, I moved all the plants away from the windows and into the center of the room, and grouped them all together. That meant setting up a couple of card tables so I could have plants under and on top of the tables. Then I'd cover the entire setup with a clear plastic tarp to form a tent, like you would use for painting. I'd use cheap bamboo sticks in the top pots so the plastic tent wouldn't be laying against any leaves or flowers.
Away from the windows and no direct sun, they're using less water. Grouped together kept the humidity/moisture levels higher. And the plastic over them kept it like a terrarium, keeping the moisture within the tent. They'd last 3 weeks without watering, I never had to try for longer than that.
