Thanks, Ben! Hope to meet you sometime.

Seriously consider the area around Montpelier, Vermont, esp. for the time of year you're talking about. I've never lived or cycled there, but it has a stellar reputation here in the states. Lots of climbs and loops (e.g., Smuggler's Notch). Also not far from major cities you might want to see (NYC, Boston), close to the Canadian border (a day or two in Quebec would be nice), and the Hudson River valley (think revolutionary war sites like Ticonderoga and Saratoge) and Lake Champlain are also close by.