Awesome locations to train

Fargo, North Dakota.

Seriously, though, it is very flat and mostly treeless, which means the wind is usually blowing.

^  Yep, have lived in SD, ND and WY. Plenty of flat and plenty of wind!

And in IMO very beautiful!

Montauk, NY

Phoenix, AZ.  Little warm, but you'll get some wind, have access to hills if you get bored.

Bring water bottles.

ditto

Maybe the grass is always greener on the other side of the fence, but I wouldn't spend 3 weeks of vacation riding on the Queen K.  Awesomely paved roads, but good gawd, it's just miles and miles of lava fields.

But maybe that's what the OP is into.  I guess my idea of a nice riding area would be totally different because I would love to go through some mountains rather than stick to flats.

True, but it would be really easy to island-hop and get in a lot of really beautiful scenery!!!

I'm having a blast training here in Melbourne, Australia!  I ride ~150-200km each weekend along the ocean, small rolling hills most of the way, but not too difficult.  Lots of other cyclists and the weather is perfect. 

A bit closer to home for you, I've had friends ride from LA to SF over a week. 

If you're looking to go all out, go to French Alps and ride through the mountains for 3 weeks.  If you have the time off, I'd go all out.  No sense taking it easy on flats, you'll get much better benefit on the hills!

We did a family vacation on Sanibel Island and Captiva Island, FL last year and it was amazing.  Not to mention the open water swimming or, if you prefer, the 50M pool on Sanibel!  I HATE flat terrain and this is the only place I could see myself living and training full time.  The beach is stunning - sea shells like you've never seen!

To get there the flight is into Fort Myers.  In addition, it's totally easy to do day trips to the Everglades and weekends to the Keys!

Andi

I really enjoyed running while my family and I were in Napa, CA, last year. I didn't take my bike, but the valley was flat and very beautiful, combined with some MONSTER climbs if you need some variety. Being an East-Coaster the scenery was very different from what I'm used to. 

...The wineries were nice too...

There's always the midwest.  Illinois, Indiana, and Ohio are corn and soybean land.  I recommend NW Ohio for uber flatness and plenty of wind. 

Melbourne, Victoria, Australia.

Wow, thanks for all the replies!  I wont get an opportunity like this very often, so I really want to go somewhere that will be a great place to train and also have fun.  Would love to hear more suggestions.  Here is some more info on my situ:

- My 3-4 consecutive weeks off is not for another 6 months.  Our first child is due in 1 week!  My wife will stop working, so her and baby Claire could be with me the whole time or just part... but I may have a hard time convincing the wife to go too far from home (like australia or hawaii, although wow... exciting thinking about that!).  We live in TX and somewhere within 2 days drive might be best.  

-I'm a definite scrub.  Just got back on the bike after 2 years off (wife grounded me until I impregnated her... ha!)  But, this year is my shot at a full IM.  Looking at B2B at end of Oct (which is usually flat & windy).  So, would love to go somewhere that I can log lots of bike miles but also run/swim.  And a location where my wife wouldnt be too bored when I'm training would be nice.

-Wife gets a little nervous when I ride on the road solo, so somewhere with wide shoulder or bike lanes would be a bonus (although not necessity).

-I've got a free place to stay in Keystone, CO... I'm just trying to find out if there are any routes that are fairly flat... not sure if that's possible since it's in the mountains... but looking into it.

So far I like the Florida suggestion, so gonna look into that as well.  Thanks for the help guys!

I was going to suggest Florida for the flat & wind, but now that you mention you've got a little one on the way and a wife who gets nervous when you're on dangerous roads, I'm not going to.

The midwest?

Okay, realize Italy may not be in the cards for you right now. In that case, I recommend my hometown of Eugene, Oregon. There are lots of flat routes, depending on which direction and how far you go. I only ride outdoors there maybe four weeks a year (winters are yuck for cycling), and some routes are incredibly beautiful and peaceful. The local cycle club (GEARS) generally does one or two flat rides a week, as well as some hilly ones, and out of towners are welcome to join. Rolling and brutally hilly also readily available. Great, essentially flat multi-use trail about 25 miles south of town in Cottage Grove. If you don't mind a little hill action (rollers and one biggie), the Aufderheide route about 30 miles from town provides about 50 miles each way of cycling bliss with tons of potential picnic spots en route.

Other benefits include perfect weather (it rarely rains July through October), clean air, and, of course, unbeatable running routes, including a big network of wood-chip trails.

LOVE this area (which makes two suggestions for it! ) and the biking is safe there unlike some other areas of Florida (Naples, anyone?).

Andi