although that ball joint is a part of your car's suspension, it will definetly affect your ability to correctly steer the vehicle if it separates. i'd err on the side of safety and either drive slow and easy with a friend trailing and with flashers on, and go to the repair shop or have it towed there for a proper inspection. (and hope you don't get ripped off). (make sure you let the tow operator know what's wrong with your ride.) to assess how bad your ball joint's condition is, you have to jack up the side of your car that the suspect joint is on to the point where the tire is off the ground about an inch or so.. (remember, safety first!) then, stick a pry bar or some such under the tire and leverage the tire up and down to load/unload the joint. then, grasp the tire at 9 and 3 0'clock and jiggle the tire from side to side to determine if a loose wheel bearing is the actual problem or not. you'll definetly hear a loose bearing doing this. if you hear a loud clunking noise from the joint, then i'd get it towed. if there's no noise coming from the joint (and you did this inspection routine properly) you could maybe consider the aforementioned slow ride to the shop if you're willing to risk it, but remember, disaster could be right around the next corner if the joint decides to separate and then you'd lose steering control in ice conditions. personally speaking, if you're not mechanically inclined, or don't have access to someone who is, i wouldn't take the chance. hope this helps.
