What you’re describing is the reason risk pools exist. Someone in a high risk pool pays a higher premium, and there is no reason that couldn’t exist with gov run insurance. Personally, I imagine something like 3 major natural disaster claims in 5 years before a higher premium, and 10 natural disaster claims in 10 years to be declared unfit for habitation. After the 3rd claim in 5 years, claimants can accept a payout equivalent to average cost of a safer regional house under the condition to vacate the area