Well, Pattaya will mostly be dry & sunny from December-February, so it will be shorts & T-shirt weather.
The coffee shops & restaurants are very likely to be open.
There will be a nice selection of lads on Grindr, including from Laos & Cambodia (some have been there the whole time).
The beach will most likely be open.
Massages WILL be available (either legally or discretely)

The big questions are:
1 Whether going out for a beer means visiting a friend, drinking beer out of a mug in a "restaurant" (= bar with a sideline in food) or some kind of full opening with/without hours restricted ?
2 What will the sandbox rules be ? If too restrictive, well it's time I returned to Phuket.