Advice for an huge collection

I would like an advice for the more experienced users here about an audio server handlling a huge collection. By a huge collection I mean about 2.5Tb. I understand that it is too much for a Raspberry Pi3. By now the files are hosted in a Windows machine. What would be the options and how to do it? DLNA + mopidy-dleyna?
I would appreciate any thought about it. Thanks. It would be nice to have Chromecast Audio devices around the house included in the arrangement.

I used an entry level Intel NUC with USB connected music library hard disk for my Mopidy server.