I will also endorse the Great Hall (Großer Saal) of the Musikverein as a spectacular place to take in a concert. I have been there twice for performances. I did not see the Vienna Philharmonic there, though; I saw Concentus Musicus Wien, directed by my favorite conductor, the now-deceased Nikolaus Harnoncourt.
I noticed that the Vienna Philharmonic is doing 4 performances at the Musikverein Dec 6th through 9th, but only the Dec 6th performance has ticket sales through the Musikverein. I thought that odd. So... I went looking for an answer. It looks like the Dec 6th show is the "open to the public" show, the Dec 7th and 8th shows are "subscription concerts" that require a subscription sold by the Philharmonic to attend, and the Dec 9th performance is a "soiree," which also seems to require a subscription.
There is a note on the Musikverein site for the Dec 6th performance that says:
The presale for members starts at 9am on 07.10.2019
ticket sale starts at 9am on 14.10.2019
I don't know how good of seats you want, but a Musikverein membership can be purchased on the website for 75 euro to give you earlier access to buying tickets. I did not have a membership when I bought tickets for both performances I saw, but I did get up at 3 am US eastern time so that I could have first crack at getting tickets offered when the general advanced ticket sale window opened. For one show, I got decent balcony seats. For the other show, I splurged for front row far right, which ended up being great seats for watching Herr Harnoncourt, who was 87 years old at the time.
The Vienna Philharmonic website states that for the Dec 7, 8, and 9 performances,
A limited number of returned and standing room tickets for this
concert will become available beginning on December 2, 2019, at 9:30
AM either by telephone (01/505 6525); at the Ticket Office of the
Vienna Philharmonic, Kärntner Ring 12, 1010 Vienna; or online.