I'm fit, and I consider myself to be a fairly experienced cyclotourist. I tend to ride 60-90 miles a day on tour, depending on weather, prevailing winds, and the nature of the roads. If I'm riding more than 150 miles in a day, I'm not going to be able to keep it up for a week. Granted, you may be more fit then I am, but from what you wrote, it wouldn't seem as if you're training any harder, or any more experienced.

That said, I'd second these other fellas in saying that you might be getting a bit overzealous with your daily mileage plans. Its not that it wouldn't be possible, you just might end up disappointing or hurting yourself if you think you can keep that up without some serious training beforehand. Just remember that you want your tour to be a fun vacation, not a suffer-a-thon.