I called the Driver Control Center (416-235-1086) Ministry of Transportation and spoke to an analysis.
Only NY, Michigan and the other provinces have reciprocity with Ontario.
Failure to pay a fine in all other States will not result in a conviction that will show up on one's Ontario license although it would not be prudent to drive in that State for the next few years.
The list of States at the start of this thread is accurate. The other States don't have reciprocal agreements for points, but they do have reciprocal agreements for payment of fines.