Instead of taking money out of the IRAs, you can perform Roth conversions to incur the tax liability to which to apply the tax credit but keep the money in a retirement account. Since you are over age 59½, you can take the converted amount (and any original contributions you may have made) from the Roth IRAs at any time tax and penalty free. Distributions of any earnings on the investments while the money is in the Roth IRAs will also be tax free after 5 years from the beginning of the year for which you each first make a Roth IRA contribution or conversion.
