I don't really agree with most of what has been said. Ice is one of the worst defensive types in the game, yet this team seems to be more defensively based. That just doesn't make sense to me, especially given how good of an offensive type ice can be.
This is clearly a theme team so it's not going to be as serious as a normal one (especially when the type is weak to Stealth Rock). I would flip this team around and go all-out offensive, since any kind of team like this is going to get CRUSHED playing defense.
As for your theme, I would extend it to water types since the arctic is pretty much melted anyways, lol. Besides, it would give this team potential to not be mediocre, which is a good thing of course.
With that out of the way, I'd invest in Gyarados, which resists fighters which eat ice types for breakfast, lunch, and dinner. I'd also turn that Suicune into offensive Suicune, and LO or CB Mamoswine instead of Curse would probably be of benefit.
I'd also throw in SD Weavile for late game, since there aren't any ice types that can really sweep late game at all. You could also CB it to get rid of ScarfGar early so Gyarados can sweep, since Weavile isn't much of a SDer.
I would also consider LO Starmie, which is a great way to counter MixApe and do some damage at the same time. Vaporeon does the same thing, only it can provide Wish support to help with your SR weak team. There are a few good options to play around with...I would look at them and seriously rework this team. As it stands right now, this team is going to get clobbered.