Quick answer: no — Minnesota does not let a surviving spouse add a deceased spouse's unused exclusion to their own. Run your own numbers in the Minnesota estate tax calculator.
One exclusion per spouse, no exceptions
Each spouse receives a single $3,000,000 exclusion. If the first spouse to die doesn't use all of it, the unused portion simply disappears — it cannot be carried forward or added to the surviving spouse's own exclusion, the way federal portability works.
A real alternative Minnesota does offer
Federal and state elections can be layered
Taxpayers making a federal QTIP election on certain assets can also make a separate Minnesota-only QTIP election on other assets that weren't included in the federal election — a genuinely flexible tool once you know it exists independently of the federal system.
Why this matters without portability
A QTIP election defers estate tax on qualifying property passed to a surviving spouse, similar in effect to the ordinary marital deduction, but with more control over how that property is ultimately distributed after the survivor's death. It doesn't recreate portability's dollar-for-dollar exclusion transfer, but it's the actual planning lever Minnesota gives married couples in its place.
A local probate attorney can review your estate — many offer a free consultation.
This election is irrevocable once made, and must be entered by the personal representative or executor — get it confirmed before the M706 return is filed.