You know that NAS can go in sleep mode, right? And wake up only when you try to activate them.

But what is the use-case? Only make your holiday films available to a media center? Or do you plan to also use it as a storage for other devices?

In the first case a sbc can do the trick (however can struggle if you share 4k). But I would definitely look into “real” NAS (Synology, qnas, etc.) before using a sbc.

I don’t expose my dns, because I don’t bother. I’m using Android phone, so I accept my phone is not private.

But a VPN could be a solution to get in touch with your dns.

Best advice. Set your own dns resolver, it’s easy.