Grab all the bottlecaps I can get hold of and move to Rivet City. If Super Mutants can't get in, then zombies... I mean, feral ghouls... can't do it. Regular ghouls I have no problems with, in fact some of my friends are ghouls. Slightly more seriously, move to Catalina Island in California. Far enough from the mainland that it's almost impossible for zombies to make it, very small population for its size, has its own water, electricity and hospital setups, bison available to be hunted for fresh meat and can go fishing year round.