Check out the Google Maps directions. It is a l-o-n-g drive, especially since their timings are behind the wheel timings that don't allow for food, fuel, and bathroom breaks. Still, both the border crossings avoid the worst of the tourist routes.

Friends who more or less commute from Mass to Toronto (one or more trips a month) suggest that the crossing is a tossup.

Make sure you have a "Canada card" from your insurance agent to prove that your car is covered in Canada, and make sure you have proof of citzenship/legal residence in the US. The requirements are here:

http://travel.state.gov/travel/cis_pa_tw/cis/cis_1082.html

Note that if you have been convicted of certain crimes, including DWI, you may not be admitted to Canada.

I hope very much that your emergency passes with happy results for you and your family. This is a tough trip to make on short notice.

Thanks for the reply Ackislander. We have actually driven it twice before, but without the rush. The first time we drove through Canada and I can't remember which bridge we took over. We took a different one on the way back, can't remember that either. The second trip we took with our granddaughter so we went the US route and stayed overnight in Ohio.

This trip will happen sooner or later, hopefully we won't have to do it until July, which is looking better for us now instead of next weekend. So I will investigate, but we will probably still do it in one day.

I would do the Ohio route, if I were in an emergency situation. No papers or insurance hassles, no border difficulties if the authorities are feeling shirty. It's longer but predictably longer.

Having driven from MI to ME last fall, I would recommend NY turnpike to Buffalo, cross to border, QEW thru Hamilton to 403 expressway, divert beyond London to Sarnia/Port Huron, over to I-75. Boring but fastest