The change I would do to Ice is not the type resisting some other type, but instead trading the weakness to Rock for Rock resisting Ice instead. This benefits both types, since Ice Mons would be able to use items that are not Heavy Duty Boots better, fully unleashing their offensive potential. Meanwhile, Rock (another weak type with 5 weaknesses) at least gain a new resistance. The sad thing about Rock types is that their most useful move, Stealth Rock, is learned by a lot of Mons that don,t have to use the bad defensive type, so if they gained another resistance, they would be more attractive.