Dear LH/ OS Professionals!

Sorry mostly BA flyer but given their limited schedule to VIE choosing OS for a flight Dec 3rd.

Departing 815pm from VIE to LHR, which lounge would I visit with a Business ticket (otherwise no LH status)?

Had a look on their website but they say G lounge (non-schengen) closes at 130pm. Will stay longer at Christkindlmarket if there is no lounge access...

Thanks!