What would the climate of Mars be (due to distance from the sun) if it were more Earthlike?

Colder.

One of the pieces I read regarding the scientific accuracy of “The Martian” last year talked about the distance from the Sun would mean not as much solar energy reaching the planet, and that the potatoes would grow but not be as robust as on earth.

Climate also depends on what’s in the atmosphere.

The atmospheric pressure is about one thousandth of Earth normal, so it takes a bit of effort to imagine a climate. Dust devils rule the land on Mars. That indicates electric charge and not enough atmosphere to restrain its effects.