Hi James,
In the LDS a marriage can be either civil or in the temple. A civil marriage only lasts until death do they part. A temple marriage is for time and eternity. A woman can only be sealed to one man in the temple. If this was for example, the case with her first husband, the other 6 would only be civil marriages, and she would hence spend eternity with the 1st.
On the other hand, if a man marries, and his wife passes on, he can get married to another in the temple. So it will be that as many women he marries in the temple, thats how many wives he will have in the eternities.
This was a doctrine that I silently accepted as a mormon woman, but battled within, until I finally left the church 5 years ago. I am now divorced. If I decided to stay in the mormon church, I would not be able to marry in the temple again, but my ex-husband would. The only way I would be granted a temple divorce, is if the prophet himself authorised it.
Being granted a temple divorce is a tricky affair - interviews with the priesthood, who then forward the information to the prophet, if they see fit. Likewise, having your name removed from the records is also an ordeal, involving the completion of documents and a series of interviews, where they will try and to convince you otherwise.
I have chosen at this stage, not to do either. Why not? Because my ex husband who was the bishops protoge was abusing us, and I asked for help, but the bishop refused to believe that he was capable of these things. It is him that I need to go see for my first series of interviews. This coming from a man who receives revelation directly from God for his fold. It was devastating to me to say the least, and they believed me only once evidence had been documented officially. But it was too little to late, and just another in a series of confirmations that this church was not what it claims to be.