Hmm. That cold tundra description is giving me some ideas. You could use an earlier historical period for you cultural base, and resource gathering is still a major concern. Would the people be nomadic, constantly traveling in order to find fresh food sources? If so, they would stick to small bands (around two dozen). Alternatively, they could be semi-nomadic, spending summers in one 'village,' and winters in another. You could scatter lakes across a broad open plain like in northern Canada, and border the south with mountains like in Russia. If the magic were animist (shamans, not wizards), you could set a compelling story against a backdrop of inter-clan politics.

Whatever you go with, have fun and keep us posted!