We're about to do this (first time!) - We have 15 days in total and will be driving over 3 days (both ways) so that we are driving for about 8 hours a day. That allows for a couple of stops as well as any delays due to weather or construction. We have two teenage kids so while I've got the ps3 and dvd setup for the rear seats, I think a a short stop every 2 hours or so should be good.
My main concern is winter driving and have hence chosen to go via I-75 all the way. This seems to add a few hours to the trip, but from what I can gather, is probably a safer bet than via Buffalo.
I'm going to keep the snow tires on and have got a copy of Along the I75.
Any tips, suggestions would be highly appreciated.