The analysis given is wrong and does not account for water borne diseases such as malaria which would become a serious problem. One of the reasons the pilgrims landed in Massachusetts was that it was north of the area that was known to harbor water borne diseases and the Massachusetts had one twentieth the number of deaths from water borne diseases of the Cheasapeake area.
The analysis presented might kill you.
If SHTF, I am heading North for this reason.
Well, personally, I think the main reason the Pilgrims landed at Plymouth was it was N of the limit of their charter corporation’s authority (New York?). So they were therefore not bound by the contract of their corporate sponsors. Of course “officially” it was because they could not get S past the shoals off Cape Cod.