Siberia recently suffered some of the worst wildfires on the entire planet haha. I think probably the safest would be East Canada as they're cold enough but not as tree-like.
Right, but that's a global cost for a localized benefit... which is kind of the whole deal here. In any case, basically every mitigation is still going to involve massive amounts of concrete- and diesel-related emissions, whether it's new housing, flood control measures, new energy sources, carbon capture, etc etc.
Well, I doubt Siberia will be ok. Northern passage will become commercially viable but the Taiga forest itself will most likely be burning for the next couple decades until it's all gone. So unless people walk 24h in oxygen masks it will not be a nice place to live.