North American races apart from Chicago I guess are always risky because of the weather and because at the smaller races you'd definitely be running alone. CIM is a good one, but the weather in recent memory has been bad as often as it has been good, and it's a bit undulating, in my opinion. I'd stick with something in Europe, even Dublin (October), Florence (late November).
Houston no longer has money though it is perfectly timed before London (January). I've heard good things about Austin (February), but have no first-hand experience.
Good luck!