But if you already have your Thailand Pass approved for Test & Go, this will still be honored.
There has been some rumors about these being honored until January 10th, and then the arrangement would be cut off, but that is NOT true.
If you have your Thailand Pass approved, it's approved until officially stated otherwise.
Your best option would probably be the Phuket Sandbox.
Here you'll have a mandatory quarantine in your hotel room until your PCR-test comes back negative. After this you can freely travel around Phuket as you please.
Your entire stay must be booked at a certified hotel, and you can't travel away from Phuket ( unless out of the country ) for 7 days. After the 7 days you're free to travel to the rest of Thailand.
Unless you want to spend a full week in a hotelroom, Phuket Sandbox is the way to go for now, unless they reinstate Test & Go tomorrow on the 4th of January. I think it's doubtful they do, but unless you're in a hurry, maybe wait and see.
Now, I don't actually know how the Phuket Sandbox works 100%.
But I think you book a hotel, and then book tests and transportation through the hotel again. But hoping someone can chime in and correct me on this if I'm wrong.
Here's a list of hotels certified for the Phuket Sandbox