Did you post an ATL about Mormons in Palestine? Or was that someone else? Sorry if I don't remember. I've actually seen a timeline that follows that idea, very interesting.
As the resident Mormon of this forum, I say that you have a very unique group of people to play around with. Anywhere they are sent, others will eventually follow, ending up in a huge colonization and organization movement. You have a source for conflicts, new nations, and stronger ones.
The Mormons had outposts throughout the entire western United States, mind you. Though it would hurt them substantially, they could move anywhere. I like the idea of the California valley, where they might flourish much better than in the desert of Utah.
If you want to send them farther away, Chile is a great idea, could add some color to the nation. However, this will weaken their religious movement considerably, as less Mormons will afford for the move and many could die on the trip or during colonization efforts.
Another idea someone brought up was to send them to Japan. The Japanese never converted in the earlier days of Catholic missionaries, because their ancestors were left going to purgatory. Mormon religion is huge on the veneration of ancestors, and the upholding of their memory. It would be a hit in Japan if there was an increased, earlier missionary effort (or exodus to the islands).
Otherwise, Canada might be a good idea, as well as Mexico (a big Mormon area), or even northern South America.
They didn't make a lot of converts, but they brought the practice of smoking weed to Utah...
Well, with the Word of Wisdom, smoking in any way is a huge sin in Mormon doctrine... I wonder what these guys were doing.