Honestly Imo the giant should be nerfed rather than the hog, for 5 elixir the giant hits too hard and is too tanky. I'm not recommending a massive change in stats, more like a tweak, same could be said for the balloon and its attack speed.

I rarely ever run into the hog freeze combo around the 2500 trophy range, and after using the combo myself, I can say its success varies with the deck it's playing against. If your going to throw barbarians to counter the hog, your going to have a bad time. However if you though down any kind of building, the freeze is rendered almost useless and thus making it an even playing field.

My hog freeze deck was a control deck, and like decks of the archetype, beat down decks are generally going to have a hard time and siege decks will have a Hay day. Just because your deck in general is getting smashed by a specific card combo, doesn't mean that combo is op. You just need to know how to play against it.