As has been determined via PM, BigJohn is looking at visiting New Hampshire during bike week. If he didn't have a specific destination I would tell him to just enjoy Upstate NY and VT and steer clear of Cow Hampshire altogether that week. But being from Spearfish, SD, in the shadow of Sturgis, I'm sure he is used to sharing the roads with the HOGS.
I would agree with yamafitter, cross the border at Ogdensburg. You could also go further east to Cornwall, but the route there will bring you closer to Ottawa. Don't go down to the Thousand Island crossing. We made that mistake coming back from CFR Huntsville. That one gets busy and slow.
For "must ride" roads on your way, the river roads on the east side of Lake Placid (Lincoln Pond Rd, Ensign Pond Rd, and of course Tracy Rd) are among the best in the northeast.
Crossing VT I would have recommended Rte 125 across Middlebury Gap, but since Russ said it was under construction, another good gap road across the Green Mountains is Route 73 across Brandon Gap. That puts you into the village of Rochester where you can pick up Bethel Mountain Rd across Rochester Gap to Bethel, VT. Those two will give you some flavor of why we love the green mountains so much.
For you to hit any good roads in New Hampshire is going to extend your day too much. You'll be at 8 hours of saddle time before you even cross into NH, so you may want to jump on a major road east from there (maybe run straight across Rte 25) to make time, then explore New Hampshire the following day. I'm sure your host in Ossipee knows all the local White Mountain roads and can show you around while avoiding the hoards. If not let me know and I'll send you a nice White Mountain day ride loop.
Here's a
dropbox link to a GPS route from Ogdensburgh to Center Conway.