As relatively impossible as it would be to take over New Zealand as a Christian nation, I suspect it would be easier.
Alaska might be easier except the USA would prize it's military options there and Russia expects to get it back in WWIII anyway.
Tasmania might be an option but there's a lot of freethinker types there, too.
Nepal might be interesting but with the Maoists and fierce Buddhists, it's probably not a remotely good option either.
Sri Lanka similarly.
A bit hard to grow crops in Antarctica still and all those rabid greenies wanting to have hands off on the place would be a nusance anyway.
Cuba seems to be taken.
Puerto Rico is rabidly hostile to anything sane plus having a plethora of ET's and government types running around above ground, below ground and under the sea. Messy.
Arizona might be possible but given all the influx of elderly liberal airheads from New England plus the masses of Mexicans flooding across the border . . . increasingly less attractive.
Idaho has attractions. But given Yellowstone blowing it's cork; a huge number of LDS and no small amount of rabid militia groups--there's more than enough complications to look elsewhere.
The Mormons are well entrenched in Utah. Besides, it's supposedly going to be mostly underwater by the time geologic changes settle down.
Iceland? Fiercely protective of their status quo.
Cyprus? Might even unite the Greeks and Turks to have a 3rd group to oppose!
Greenland? Farmingly challenged unless global warming goes bannas in a big rapid way.
Nova Scotia? Pretty parochial about their status quo, too. Besides, a little too close to the Rabid Frenchies.
Methinks that just about leaves . . . let's see . . .
some corner of Amazonia . . . . Argentine or Chilean highlands
or . . . . thinking . . .
. . .
Come quickly, Lord Jesus.
If things get too bad, Ireland is an option, although they manage to remain Conservative traditionalists by tight-fisted immigration laws that keep out a lot of people who'd want to come there.
Until you get to Heaven, there's always the Upper Peninsula of Michigan . . .
You forgot Bhutan.