You do not need to be separated for any specific period of time before you can file for divorce in Minnesota. In fact, you can remain living with your spouse at the start of the divorce, during the divorce and after the divorce is granted.
Some states require a specific living-apart period before you are eligible to file for divorce, but Minnesota does not have one.
Some states also have mandatory waiting periods after filing before the divorce can be finalized. In Minnesota, there are no mandatory waiting periods but there are different timelines which control how quickly the divorce will happen.
In Minnesota, Courts retain jurisdiction to hear motions to remove one party from the marital home while the divorce is pending.