EDIT: Some RVs are registered as homes, you can drink all you want inside therm. Or in a trailer.
Otherwise, you can and will get a ticket for OC. You might get arrested, depends on circumstances (belligerent, obviously drunk. Not just an open beer you haven't drank from.)
An arrest" is Technically any stop, detainment by a cop. If you ask: "May I go?" and he says :"No", it's An Arrest.Even an infraction,
Those who say: "DUI" .. "same as DUI", "functional control..".. NO. Some states try to call it "DUI" if key within reach of driver and over legal limit. If key in back seat, they cant. Beware. They Legally have to see motor running. Takes good lawyer to get them off your back, I know one who plea bargained, the car was disabled, asleep in it. Parked in a Private lot. But that's AZ for you.. A Good lawyer is $40K. No Public Pretender can get you off. Az makes $$ in Fed tax money off those sentenced to ADC