If i were to pull in at night on a friday or saturday would their be any chance of finding a spot on gecko or RR loop?

How early do you have to get there to get a spot on big weekends and off weekends? do people just pull of the side of the road and set up or do they back in etc?

I am taking a trip out in november and want to know what I am looking forward to when i pull my rig in at night.