Balefire can travel as far as the channeler can spin the weave that supports it. Rand says in FoH that 5 miles is pretty much the maximum distance that he can affect anything with the One Power.

Five miles is therefore the maximum distance that a weave of his can travel. And since Rand is the most powerful channeler in existence that is most likely the maximum distance that ANY human can create weaves with the One Power.

The strongest sa'angreal is the Choedan Kal. So as a rough estimate you can probably multiply the five miles by the magnification factor of the Choedan Kal if you want to reach a theoretical maximum distance.

So how far is that?

Well, the Aes Sedai say that the entire White Tower, using all their angreal and sa'angreal couldn't channel a fraction of the amount of saidar that Nynaeve used at the Cleansing. So lets say the fraction they are referring to is 1%.

That means Nynaeve channeled 100 times the amount of saidar that the entire Tower can channel using all their angreal and sa'angreal.

Let's make that 1000 Aes Sedai, and multiply that by 2 to cater for all the angreal and sa'angreal in the Tower. That brings you to 2000 Aes Sedai.

That means that Nynaeve channeled 100 times as much as 2000 Aes Sedai during the Cleansing. That means she was the equivalent of 200 000 Aes Sedai.

And yet, we are told that the amount of saidar used at the Cleansing was like a foothill next to a mountain compared to the amount of saidin channeled by Rand. So Rand might quite easily have been channeling 5 times as much saidin as Nynaeve was channeling saidar at the Cleansing.

Meaning that Rand was probably channeling the equivalent of 1 million Aes Sedai at the Cleansing.

To go further, Sanderson says that Rand channeled more of the Power on Dragonmount than he did at the Cleansing. So let's double it again, and we get to a rough figure of 2 million Aes Sedai as the maximum that the Choedan Kal would allow Rand to channel.

Given that Rand is probably at least 5 times stronger than your average Aes Sedai, we can divide the 2 million by 5, getting us to a nice round figure of 400 000.

So there we have the answer. The Choedan Kal can multiply Rand's strength by 400 000.

Therefore his maximum range of 5 miles can be multiplied by 400 000 using the Choedan Kal, bringing it back to 2 million miles.

So there we have it. Rand can weave balefire that travels 2 million miles.

He can balefire the moon out of the sky without breaking a sweat.

So then the question is:

Would the guy who had been surfing the high tide at noon still be wearing his wetsuit, given the fact that the moon's thread had been erased a few days back in time, and there would thus not have been a high tide?

Another unsolvable paradox.