I was thinking of rundown ghoul infested manhattan, or a fallout game that takes place in minnesota in the winter. Doesn't have to be limited to the U.S though, interested in hearing some other locations that would make for a cool fallout game.

Let's mosey on over to this thread http://www.gamesas.com/index.php?/topic/1155916-official-fallout-4-location-suggestions-3/.

the heat-drenched Australian Outback.

Yes, please use the thread so kindly linked by Colonel Martyr.