Provided that your charitable deductions after your death bring your estate value below the Massachusetts 1 million dollar threshold, there will be no estate tax due in Massachusetts. A Massachusetts estate tax return will still be required to be filed as your taxable estate started at an amount above a million dollars.
If you would like to avoid your heirs filing an estate tax return, you would have to make withdrawals from these accounts, take the charitable deduction on your 1040. However, there are charitable deduction limitations applied to lifetime gifts, which is generally 50% of your adjusted gross income. You should work with a CPA or tax attorney to determine the best way to spend it down.
Also, please remember that end of life care is very expensive. An assisted living can run close to $10,000 a month. So while $1.4 million sounds like a lot, you can easily spend that down below the million tax threshold to avoid entering a nursing home.