Sequoia looks interesting.
Hi there....new kid here, so hello
I stayed at Sequoia about a month back and it is excellent. The restaurant at Mount Lofty House was great also.
6-7 days is a good slab of time to explore the wine regions around Adelaide.
In the Barossa, the JHA Stone Cellar on Hutton Vale Farm is excellent as a base.... the farm is wedged between the Hill of Grace and Mount Edelstone vineyards....and the Angas family are wonderful hosts (Disclaimer: I lived in the old 1842 stone cottage on their 2000 acre farm for 8 years so I know the family really well.)
JHA Stone Cellar
I'd aim for a weekend in the Barossa.... maybe Otherness or Vintners for dinner the first night, farmers market on Saturday morning to stock up for a dinner.....visits I'd aim for Henschke and Yalumba in the Eden Valley.
Rieslingfreaks new cellar door is lovely if you like riesling and you could basically spend a day just doing visits on Krondorf Road with St Hallett, Rieslingfreak, Rockford, Charles Melton, Ollin Wines and Eperosa.
Alkina in Greenock is a great visit if you like grenache (great accommodation too) and Seppeltsfield is amazing for a lunch at Fino, a tour and a chance to try the 100 Year Old Para and try your birth year fortifieds.
The best visits are the ones you have to work for and are tasting by appointment e.g. Sami-Odi, Standish, Agricola Vintners etc.
I'd probably aim for a night in Adelaide to arrive with a visit to Magill Estate. A night in McLaren Vale (only 40 minutes drive from ADL) and knock out 4-5 winery visits. Leave Mclaren Vale and head up to the hills via Kangarilla, Meadows, etc and knock out visits up there (Shaw + Smith, Deviation Road, Ashton Hills, Tapanappa, The Lane, Petaluma, Pike & Joyce, etc).
Continue to the Barossa via Woodside, Birdwood, Mt Pleasant, Eden Valley and veer off there towards Keyneton and visit Henschke, then Yalumba before settling in at your accommodation.
A couple of days in the Barossa (shout out if you need winery recommendation or contact details for appointment tastings), then up to the Clare Valley for a couple of days.... it's quieter and less travelled than the Barossa and M Vale,.... jump on a bike and do the riesling trail, sit under the olive tree at Skillogallee and have lunch, drink your bodyweight in riesling and then amble back to ADL and home.