By today's JW standards, Solomon could find himself in the Kingdom Hall's back room, answering to some judicial committee.
'Unhappily, however, like the values of so many leaders today, Solomon’s values eventually changed. The Bible account reads: “He came to have seven hundred wives, princesses, and three hundred concubines; and his wives gradually inclined his heart. And it came about in the time of Solomon’s growing old that his wives themselves had inclined his heart to follow other gods; and his heart did not prove to be complete with Jehovah his God like the heart of David his father.” '—1 Kings 11:3, 4. Awake! 2003, 6/8 p. 9
Then, again -- by today's JW standards, Solomon will probably be resurrected.
'What happened to Solomon when he died? The Bible answers: “The days that Solomon had reigned in Jerusalem over all Israel were forty years. Then Solomon lay down with his forefathers, and was buried in the City of David his father.” (1 Kings 11:42, 43) Hence, it seems reasonable to conclude that Solomon is in Sheol, or Hades, from which he will be resurrected.' The Watchtower, 2005, 7/15, p. 31
Watchtower reasons his destiny based on the expression, "Solomon lay down with his forefathers".
Sounds fair to me: haul him into the back room for the practice of egregious transgressions -- then resurrect him.