I've played only the original DoTA, and it's possible there. You can either play solo against a single AI, or have n AI heroes in the opponent team and (n-1) AI

I've played only the original DoTA, and it's possible there. You can either play solo against a single AI, or have n AI heroes in the opponent team and (n-1) AIs in your team - I'd recommend the latter with n=5. The AIs play like an intermediate level player (albeit with a few exploitable weaknesses).