Hello - I'm from Ottawa and we've done the trip numerous time in one shot. Ottawa end's up being a little bit farther then Toronto.
Load-up the car the night before, leave at 4:00 am. We usually arrive in MB around 8:00 - 8:30 PM. Still a bit of light, enough to go for a quick walk on the beach just to let the pressure off and the let the body change gear to "slow".
From Toronto, I would drive down to Buffalo, then to Erie (HWY 90) and head straight down HWY 79 (if you leave early enough, shouldn't be a problem through Pittsburgh) , until you hit HWY 77 (HWY 19 is a good shortcut).
Then 74 to Winston Salem. You're just about within walking distance then! nanner
I think that's what the poster above recommends also. Total distance is about 1500km.
Take a look at this itinerary from Bing...
http://tinyurl.com/krm2wb
(I don't understand the bit about not driving in WV?? It's only for ~2hrs)