I personally wouldn't do it, because it can stress a snake out, especially if they battle for the same hot spot. I know people have done it, but I wouldn't. This is my take on it regarding ball pythons. I'd only do it for breeding purposes.
However I do have 3 rufous beaked snakes that I have living in the same tank, it's very large and I have it setup so it has multiple hot spots. Though it doesn't matter because they're always together when out and about.
Yeah I wouldn't recommend it either. If prices for a second enclosure are to much just switch to Rubbermaid or Sterilite Tubs. They are better at holding in heat and humidity anyways. Tubs all the way.
I personally woun't do it outside of breeding purposes, but others will say different. Only time I've heard it recommened though was from someone at an expo trying to sell an animal to someone who didn't want to have to buy a seperate cage.
Where are we going, and why am I in this handbasket?
Never argue with idiots. They will drag you down to their level and beat you with their experience.
Artificial intelligence is no match for natural stupidity.
I wouldn't do it with BP's. I do have two baby garter siblings cohabbing in a 20-gallon tank, but they're more social than BP's and we find groups of them hiding under stuff outside all the time. They're both still smaller than a nightcrawler so there's plenty of room, there are multiple hot and cold hides so no fighting over resources, we separate them for feeding, etc. They'll be separated shortly as I do NOT want to breed garters.