Not that easily. Promotions (in FfH, not FF) cannot let units move impassible without giving them the full flying ability, which also won't let them use roads.
Another approach would be letting Ice be passable, but requiring resistance to Cold damage to pass though. It would basically work just like Flames. Features that require resistance always require 20% resistance, so Magic Immune, Magic Resistant, Cold Resistant, or Winterborn would make it passable to units of the right domain or with water walking/flying. Currently no water unit can get these promotions, so it wouldn't make a difference for them. Water walking could be made to give cold resistance, but then it would be the best counter to Blizzards. However, it would mean that Flying units could no longer pass over the ice (without a promotion to give resistance to cold, that is). It would also mean that cities could work ice tiles for full yields, unless the feature were given negative yields to balance that.