Cold can be mitigated a lot by enhanced R-value insulation in a single application. Northern states have higher levels of insulation.

https://www.energystar.gov/campaign/seal_insulate/identify_p...

I don't really see a hot/cold stratification in this chart-

https://www.statista.com/chart/12098/the-us-states-with-the-...

And even then, the difference in costs seems quite small. Alaska is $332 and Georgia is $310.