I'm not sure that I understand the question but the L-1 for Canadians is still a very good option and can be obtained even for brand new companies/offices. Once you are in L-1 status, you can be paid by the U.S. company or even just continue to be paid by your Canadian company.
How can a new company qualify? I "freelance" through a Delaware-corp I registered a couple of years ago. I am a Mexican citizen, not sure if that changes anything.
Self-sponsorship is prohibited in the TN category (as well as other categories) so this isn't possible unless you have co-founders and co-owners and are treated as an employee.
