It took me around 6 hours of walking to get there. (using wander, and stopping occasionally to kill rabbits for food to keep my phlegm up) It takes me about two hours of travelling in the opposite direction to get to edge of the map. Assuming boston is in the middle of the map, (north/south-wise) I'm guessing it'd be around 12-14 hours to go from the bottom edge of the map to the top edge. (again, using wander)
P.S.
Yes, after I walked 6 hours in one session to find boston I wanted to kill myself.
