No way am I paying those off early - even though I could.
Instead, I took the payoff money and put it in short-term (4-wk) T-bills paying around 5.4%.
It's a small form of financial arbitrage - making over 3% return between my debt and the government's debt.
Good move—it is heads you win tails the mortgage lender loses.
If interest rates go up your arbitrage reward gets higher.
If interest rates do down you can always pay down or pay off the mortgage.