Much of Hyder will be closed in October.
Meziadin Lake provincial park campground shows as being closed then too. I expect the campgrounds in Stewart will be the same.
Salmon Glacier is a worthy visit. However, in October it is possible there will be snow at the higher elevations. The road is not maintained up to the glacier viewpoint. Being a coastal area, the snow can be deep and wet up there.
I'm thinking even the bears will be in the hills settling in for winter hibernation.