>>36337187I personally think the scarcity of cold zones has to do with GF's mentality regarding ice types.
Ironically, they've always seen ice like this strong, dragon killer type that is supposed to be very rare to find in the wild. So, despite how wrong they are about this (really horrible defensive type, let's make most of them slow and bulky!!), they have a tendency to put these mons in late games.
And since they're supposed to be rare to obtain, it's natural from a design standpoint they'd think their biomes should be equally rare.
Also, posting another route I like.