You can delete a state
return in TurboTax Online, as long
as you haven't paid for it yet (or registered in a free
version).
To see how to delete your Minnesota state tax return, please see
the following TurboTax FAQ, "How do I delete my state return in TurboTax
Online?":
https://ttlc.intuit.com/replies/3301384
Once you have finished working on your Wisconsin return, you can then re-add your Minnesota return.