HomePod without wifi?

You cannot set up the HomePod without access to Wi-Fi and the Internet. Once configured it is possible to AirPlay from an iOS device to HomePod over an ad hoc connection that doesn't need an additional Wi-Fi access point. See the Change AirPlay settings section of Change settings for HomePod - Apple Support. Using Everyone, probably with Require Passcode, should do the trick.

tt2

Hmm, just testing this now and it works, but not with stereo paired HomePods, and it can only play to one device at a time in this mode.

tt2

You're welcome. 🙂

tt2