A Green Card is a visa with permanent intent. A TN visa has temporary or limited intent. At best, such a transfer would signal that your TN was not pursued with temporary intent.
In my IANAL experience as a Canadian who immigrated to the US, you need to transfer to a permanent intent visa like an H1-B from which the conversion to Green Card is more straightforward. Alternatively, marry an American.
In my IANAL experience as a Canadian who immigrated to the US, you need to transfer to a permanent intent visa like an H1-B from which the conversion to Green Card is more straightforward. Alternatively, marry an American.