So, in the historical context, polygamous Mormons lived as polygamists until their deaths. Does this set a precedent for those who are converts in polygamist relationships?
Jack answered this but I'll add a little...
If a man in (or from) another country with numerous wives wanted to join the LDS church he must divorce all but one of his wives.
To join the LDS church a man is allowed one and only one living legal wife. There are no exceptions.The divorced wives, are divorced and can remarry as they wish.
Now, I know of no restriction from the LDS church of a man living with numerous women in the household so long as they are not having sex and are not legally married. It would be similar to having a family allow a MIL, Aunt, sister, or SIL, live with them.
I think this sort of situation would be unusual but I suppose it is possible. To be honest I find it hard to believe it would ever come up, but I suppose anything can happen. :-)
~td~