well, i have a specialized tarmac, and a specialized rock hopper. Will probably ride the rock hopper, its all dirt roads(6.5 miles) untill i hit a bike trail then its bike trail the remainder of the way. Typically, when summer time comes I don't have a problem riding 150-200 miles in a week. I don't have to commute, but it will be something to put in my training schedule. I have time for an extra 2-3 hours a day. I can ride 100 plus miles in a day, i've done it.
I don't plan on going all out the first week i realize that it is undoable, i would work my self up to riding like you guys have mentioned aboved. I don't know if there are showers there yet i start in late march...