denmark

No, Texas can't even secede from the US and we barely want them. All the land is already taken, you'd literally have to kick someone out of a country and that's illegal in international courts. Sorry, Antarctica isn't taken, and at the rate of climate change the ice will melt away at some point to see the earth beneath but I haven't done the math to figure out if it'll be below sea level when it rises.

Move to Denmark, Norway, China, or the Czech Republic, they're pretty heavily atheist and non-religious. I'm pretty sure the Czechs are only atheists though because "how could a supreme being possibly them over so " but meh, good on them.

We could have any country. Take America for example. Get some openly antitheist to go into politics. Move them to the least religious area, create a new party and run for office. Make it clear that the party will remove religious tax breaks, religious schools and foreign clerics and improve education with rational thinking. When they're voted in, DO A GOOD JOB AND DON'T ALLOW CORRUPTION. Watch it spread from there.

No, because we live in a capitalist world run by the ruling class who hold the power.

China is the world's least religious country, with 67% self-identifying as atheists, and another 23% self-identifying as "non-religious". [weforum.org]

Currently, China, Vietnam, and North Korea practice state atheism (active opposition to religion, as opposed to a secular state that's more neutral as to religion). Most communist countries had state atheism. Mexico and France did at one point also.

"The Republic of Coastal America."

I don't believe something like that would be possible. Nor should it be.
Atheists are everywhere, just like believers.

No. Theists control policy.

Personally im hanging around in the hope of getting to Mars. Go SpaceX. Lets make the red planet atheist.

And abandon the rest of the world to ignorance and theocracy? Never. We owe it to the yet unborn. Also, what would be done with the weak-minded in this brave new world who succumbed to ancient superstitions?

Probably easier to just move to an already religious free country. Excluding china, the top 4 are Estonia, Sweden, Denmark & Norway. In that order. The Scandinavian countries have a high quality of living. Dont know much about Estonia im afraid. They don't have high populations so it wouldn't take too many atheists to tip the country to officially atheist.
I'd ask you to stick around the uk though. We need all of our atheists, and we aren't much further down that list of least religious countries. Change does happen. Thing's will get better. Obviously after a lot of frustration 1st.

This is going to sound really out there, but bare with me... We'd need an island in a temperate zone not beholden to any hostile country... Then we'd declare Independence from the country that we bought the island from. We'd need every possible atheist or agnostic with any knowledge of infrastructure and the equipment needed to create it, then we'd have to form a government that heard every voice and weighed all input accurately. Then we'd get to work. We'd be laughed at until we were more advanced technologically than 3rd world Nations. That's when we'd need a well trained Army and Navy to keep from being liberated to death by the US or it's allies. And if we have exploitable natural resources, we better have that military presence in place before construction begins or we won't ever get to begin as a nation. The US doesn't like competition in any field. Sovereignty doesn't mean much after a genocide.

Hey, the Jews accomplished just that so it is definitely possible.

I don't think I would want to live in any country that banned any kind of free thought. But there are places in the world like that. This said about Russia back in the day. Maybe just a government that kept it's hands out of the citizens beliefs, oh yeah america..but that dream has yet to be fully realized even here. George Washington would have been disappointed I suspect .

The moon we leave all the crazies back here on earth and build a lunar colony with zero religion allowed.

Some uninhabited island with food and water sounds good to me.