1) Residency requirements: To file an action for legal separation, you only need to be a resident of the state of Wisconsin (and of the county you file in) for 30 days. To bring an action for divorce, you must be a resident of the county you file in for at least 30 days AND a resident of the state of Wisconsin for at least 6 months.
2) A legal separation does not dissolve or terminate the marriage, and therefore, neither party can remarry if their previous marriage ended only with a Judgment of Legal Separation and not a Judgment of Divorce. However, the parties can agree to convert the legal separation to a divorce after the Judgment of Legal Separation is entered, and either party to the legal separation can bring a Motion to convert the Judgment of Legal Separation to a Judgment of Divorce if more than one year has passed since the Judgment of Legal Separation was entered.