So....do they wander or not....

I was also wondering what they do to ride out a blizzard since they don't seem to have any viable shelter or food stored up to speak of.

Their territory is wherever they happen to be. That's what makes them a threat. They can go wherever, and when they come across people trying to rebuild, they claim those people are trespassng, and send a bunch of zombies into their camp to wipe them out. Because the true believers see the world as belonging to the dead, and any humans who want to survive must live the way the zombies do.

It's whatever they need it to be depending on how they want to twist the plot of the current episode ... this show has zero consistency.