I did this with my main when Ice Caves hit. I just moved all his stuff to a new world with the same seed.

I've been very cautious since, and I intend not to journey into Mistlands territory until the update actually hits the streets.

My second char, ready for Moder, is stuck in a wait loop, since Moder is in decidedly outer rim territory (Hutt country), where he has to pass several mistlands continents.

So he will have to wait for that. No problem, I have my fourth char to keep me busy. Or I can keep patching holes in my maps, which can also be fun.