Probably the only accessible place left where people still play notd regularly, clan zmc in the official europe server... they have 2 hosting bots that are usually online 24/7. They have now added eurobattle.net to both of these bots so anyone from this server can also join the games.
Bot 1: zmc_bot
This bot usually auto hosts notd3 non-stop, 24/7, unless someone with control manually use it.
Bot 2: zmc_bot2
This bot is usually online 24/7 also. It does not automatically host anything. So it is available for starting notd SO games or notd2 games whenever.
Anyone interested can just add these 2 bots to friends to track them. Remember that these bots hosts across different servers so you will probably see someone from the europe server using them.