I did split mine when i brought home an unexpected bp. I needed an extra tank for quarrantine, and wasn't able to get to the store. You just have to make sure you secure the thing in the middle, so if they push on it they dont fall through.
I only did it for one night. I would only split it two ways, depending on the size of your snakes. With our aquarium, their is a lip on the inside, and the divider couldn't reach all the way to the top. They can squeeze through it, so make sure there is something that they can't get through. Good luck. I stuffed a towel at the top of mine, but it was only temporary. And my female knew something was wrong, and was out investigating the new wall all night. It is possible, just make sure you cover all areas the snakes can squeeze through.