Serving pressure and temperature are ideal. Less chance of under/overshooting the carb level. If you have one tap and room for two kegs in the kegger, get a Y-connector.
Plan on a week and leave the second keg at room temperature until then so it can condition.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk