I would suggest you drive to Canada instead of take flight, if it is feasible for you. You can fly to Buffulo can rent a car there then drive to Toronto, only 100 miles. By this way, you have good chance to keep your I-94 and less risk to come back even you don't get a new H1 stamp.
You can even fly to China from Canada, then also fly to Canada from China, then come to US.
Regarding your H1 stamp at Toronto concern, I have no idea since I have no information regarding it for the past couple years