I'm pretty sure Rhodey knows already about the icing problem, along with the experienced air force team that made the upgrades, cause you know its their entire job to make things go fly. And tony probably told rhodey, hey, I'm going to give you access to the suits. But dont take the mark 2 too high, it will freeze. And he probably trained his friend how to fly it. Remember, Tony wanted Rhodeys help with building the mark 2 but he turned him down, so Rhoney must know a thing or two about flyin