I'm no expert but I used to have rabbits who where litter trained with their own room, and it was messy! If it's carpeted then it'll be torture to you. All the little poops, hay, and food spills will be impossible to clean up. And from my understanding they like to jump and climb, which is why they really need a cage with many levels. If it's a smaller hardwood flooring room, then I'd say as long as there's nothing they can chew on and hurt themselves, then go for it if you really want. I'd definitely leave the cage in there and have it open though. I follow "Mr. Bagel" on instagram and I'm pretty sure I've seen on posts that she lets her chinchilla roam the entire house all the time and she posts videos of him all over the house lol. Different things work for different owners I suppose.