I don't know where or when this is going to happen. The last 2 years it has been off hwy 4 in the 3rd week of Oct.
Checking with the local FS, I found the Federal Campgrounds will be closed on 10/12. The FS roads will be closed around the 2nd week of December. You can camp in the FS campgrounds even if they are closed. You won't have road access to most them and all will be without services.
There are 3 State campgrounds in that area. Calaveras Big Trees, Grover Hot Springs in Markleville and Indian Grinding Rock off 88, they are open year round, depending on the weather.
There is one BLM campground at Indian Creek reservoir near Markleville and several others off hwy 88 near Blue lakes. I don't know their policy. The FS says if the roads are not locked, you can access them. Whether they provide services,
Sometime in the next few weeks I will check.
Update: I checked with Sorensons, a private campground on 88 where we held our freeze your gonads rally and found they will be closed in October. The Carson river resort may be an option, but I found that their "campground" along river is only serviced by porta-potties that they bring in and remove when the season is over. I know there are no tables nor water down there.
The PG&E campgrounds may be accesable, but they are high elevation and a lumpy dirt road in.