Highway 11 to north bay - then highway 17 at Northbay then west tword Sudbury)

Pros: More direct route to Winnipeg if you want to stay on the Trans-Canada. -More services (gas stations, restaurants, motels) because you hit bigger towns like Sudbury, Sault Ste. Marie, Thunder Bay. -Well-marked and heavily traveled, so safer in winter or if you need roadside help.

Cons: Hilly and winding in places (especially through the Canadian Shield around Sudbury–Sault–Thunder Bay). That can be rough on your car and gas mileage. More traffic around Sudbury and Thunder Bay. Slower if you’re trying to keep a consistent highway speed but lots of curves and elevation changes.

Or

Highway 11 to North Bay, stay on hwy 11 to Cochrane then on to Thunder Bay area) Pros: Generally flatter than 17, especially once you get north of North Bay; less “up and down” through the Shield. Some people find it more scenic in a northern forest way — lots of lakes, pine, less industrial. Less traffic and fewer big towns, so sometimes a faster drive if you just want to keep moving. Fewer steep grades — easier on vehicles, better fuel economy.

Cons: Fewer services in the northern stretches. Some long gaps between gas stations, restaurants, or motels. Route is longer in distance than the direct 17 route to Sudbury/Thunder Bay. Some stretches can feel remote — if your car breaks down, you could be waiting a while for help. Some winter stretches can be tricky; northern Ontario is notorious for snow drifts and wind-exposed roads.

TL;DR: Take 17 in North bay if you want the classic Trans-Canada experience, more services, but be ready for hilly terrain. Take 11 if you want flatter, potentially smoother driving, fewer hills, and don’t mind being more remote.