That cage would be more than enough space for two chins. :thumbsup: Many people keep 2 chins in one half of a Ferret Nation cage, which is similar in size.
The Feisty Ferret is big enough for two chins. One thing to take note of is that only half the front is a door. The right side opens and the left side is welded shut. I don't know if this makes a difference to you or not, but it is something you should know ahead of time.