"We’re buying each other a gift this year to keep undelivered in the gift box in addition to our normal purchases."
2022 buy $10K for self, and $10K for gift for spouse. Do not deliver gift.
"If the interest rate is still good next year, we’ll buy normally and keep the gift in the gift box. "
2023 if rate is high, buy $10K for self. Still hold 2002 gift don't deliver.
"If the interest rate isn’t good anymore, we’ll skip the purchase, deliver the gift,
20XX if rate is low, don't buy $10K for self. Just deliver 2022 gift to spouse.
"and cash out immediately."
20XX since rate is low this year, once your spouse receives the gift, she cashs out.