Without anyway of controlling the speakers, unless you can ponce a piece of Meridian kit from someone and/or make up your own serial/SpeakerLink dongle, I'm afraid you are stumped until your other bits arrive.

Meridian owner since 1992
Prime & PSU, Focal Elear headphones, Roon (ROCK 8Gi5 NUC), Explorer 1 & 2, F80. 200/203, various Sonos (via Roon).