Turbo Tax has never really addressed this. Too dangerous playing with prior year files. They need to set up a "Plan mode" using proforma next year files updated during the year periodically. ie. we would have had a 2020 tax year "plan" file since April of 2020. It would start by carrying forward 2019 data and then u would edit it as appropriate. You would have the option to import this data into the 2020 tax year file after Jan 1, 2021.
