It is a tad strange to see so many ice Alola forms though when the region is based on Hawaii lol.
I never felt like they put too much thought or lose too much sleep on making the Pokémon of any given region based on animals (or things) native to that real-life location. I mean sure, we got trash Pokémon and a American Eagle for New York-inspired Unova, a french poodle Pokémon for France-inspired Kalos, and tropical based plants and animals up the ying-yang for the tropical Hawaii-Alola, but we still got a lot of unrelated-to-their-real-world-habitat animal-based Pokémon for all the games (a lot of non-Japanese themes-turned-Pokémon in the Japanese-based Kanto, Johto, Hoenn, and Sinnoh...) which I appreciate, because I don't want to have to wait for GF to eventually, maybe, maybe never, give us an Australian region for a koala or a kangaroo or Tasmanian devil...we could easily (and have in some cases) get these just whenever GF has an idea they deem worth premiering in whichever region we're dealing with.
I'm glad we got a panda, finally, but panda's have eff-all to do with France, yet Pangoro = Kalos. So what I'm saying is...it doesn't register to me personally as weird to have Ice Pokémon or even a icy area or winter climate in this tropical Hawaii-inspired Pokémon region, cause it has always felt like GF just includes the bare minimum of accuracies to these regions to get the point across that "hey, this region is New York, or France, cause of these three to five instances...now, here's a Legendary based on Asian Mythology, or a random dessert right outside the NYC-esque city!" The effort to get the Hawaii-ness feel across here in Sun/Moon, though, is much better than their previous attempts at tying their location themes to the games, but I'm still expecting anything from an African Elephant to Egyptian themed Pokémon to show up in Alola.
tl:dr: nah, Ice Pokémon in Poké-Hawaii is no weirder than Aussie Koala in the wilds of Poké-Hawaii or Asian-Panda in Poké-France.