I think A-F (above) is right in that once adultery has been committed and a divorce has been completed (not just filed) then, the man and his wife are no longer "scripturally married." On the other hand, if the man and his wife engage in intercourse after the adultery has taken place, then, she (in the WT's eyes) has given up her right to scripturally divorce him (until he commits adultery again).
The result would be (after adultery + legal divorce) that both are free to remarry in the WT's view. With this exception: The wife would not be free to remarry her ex as long as he is DFed. If she did she would also be DFed for intentionally associating (via marriage) with a DFed person.
Since the man admits to committing adultery for the purpose of being free to marry the new girl, he can expect that he won't be reinstated for many years. I think the KS textbook says this in so many words. The elders would have to wait a long time to see evidence of repentance since there was, not just a 'moment of weakness' involved in the adultery, but premeditation.