You can always make air spaced insulation layers and fill the airgap with rockwool. Considering global warming this would probably be a good idea.

Houses in Mexico are tradionally made of rock/concrete and act like a heat battery. Ie houses caputure heat during day and cold air during night traps that in rock like heat battery. Houses in Mexico from the 70s are surprisingly cool yet requieres no air conditioning.

Mexico needs some home insulation during coldest winter months.