Too much humidity inside the cabin.
Recirculate mode on accidentally? I live somewhere colder than you and I've never scraped the inside of a windshield in my life.
the recirc mode is commonly used in summer for max cooling.
Many drivers forget to turn this off in fall/winter and it leads to excessive humidity in the interior and condensation (which turns to ice in colder temps).
Living in Canada, I've personally never had this happen on my cars, but seen it on others.