Roth Conversion with IRA basis followed by IRA Rollover

I retired last year. Earlier in the year, prior to retirement, I took the funds in my Traditional IRA ($20,000) and converted them to a Roth IRA. The IRA basis for those funds is $6,600 (based on previousl 8606s). Once I retired, I rolled my Traitional 401(k) into the now empty Traditional IRA. The amount of the rollover significantly exceeded the $20,000. I then converted $53,000 of the 401(k) based Traditional IRA funds to a Roth IRA.

Here's my question. The $6,600 is directly related to the initial $20,000 I converted. However, TurboTax asks what the value is of all of my Traditional IRA funds as of Dec 31, 2024 on the screen that follows the IRA basis. The amount I enters determines how much the $6,600 is deductable for last year. Can I enter $0 since the $20,000 is no longer in a Traditional IRA? Or do I have to include the Traditional 401(k) IRA funds that I rolled over that now sit in my Traiditional IRA in the total?

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