The 403 from Woodstock to Brantford is down to one lane. The most logical way to get to Brantford is Highway 2 out of Woodstock to Eastwood, then take Highway 53 south at Eastwood. Highway 53 and through Cathcart and Burford and eventually leads to Brantford. Between Cathcart and Burford is Highway 25. It goes through a marsh just south of Highway 53, and if followed, will take you close to LaSallette. However keep in mind cell coverage is absolute garbage for Virgin/Bell in this area and there are not a lot of towers to ping against.
The 403 is down to 1 lane either way between Woodstock and Brant Road 25. The easiest way to get to Brantford from Woodstock is either taking Highway 2 from Woodstock to Paris, then Paris Road to Brantford or, what seems more likely, Highway 2 from Woodstock to Eastwood, then take Highway 53 (aka Colborne St.) which would take one through Muir, Cathcart, Burford, then West Brant. This is the route that I would take because Paris is a dumpster fire traffic wise. The other thing to consider cell tower placement. In the Burford, Scotland area, Virgin/Bell users don't have enough towers and there are large dark areas with no cell signal..thus no pings. Hard to tell where the cell truly went dead.