In theory, the innocent mate in a case of adultery is free to remarry (after the divorce, of course) if he/she chooses to divorce the guilty mate. If no adultery has occurred, then there is no basis for divorce and neither mate can remarry.
One catch-22 is that after the divorce, the guilty mate is also free to remarry (assuming the divorce was on grounds of adultery). And, it can be the guilty party who seeks the legal divorce if the innocent mate has "rejected" him/her. My ex-wife divorced me based on HER confessed adultery. She was not disfellowshipped because she was "repentant," even though she informed me privately that if I forgave her for the adultery (thus removing her ability to get the divorce) she would just go out and do it again.