Have done it in Mammoth. Bring pine-sol
Also used to be an outfit called "gettin wet gettin dirty" did same thing. There's a lot of sand down there but I hear people have done it with those 250's..
You could have quite an adventure if you hit this then Randsburg/Jawbone or some such!
There's a motel in Salton Sea, one at the Leaping Lizard (or is it the Iron Door? I always forget) which is much closer than Sslton Sea. Borrego also has motels and Ocotillo Wells park itself has restrooms and shower facilities.
My best advice if you haven't ridden here is hook up with people for sure going when you are. Myself, I am kind of flexible. I know for sure I will be there the 16th. After Xmas dates are fluid and my wife and friends are trying to pull me to Johnson Valley.
Ocotillo is an open ride area. The surrounding Borrego park has some nice scenery and I prefer to ride if bcoz this time of year Ocotillo is crowded. Desert. Camp where you like.