Item — HN Reader

http://www.cic.gc.ca/english/work/special-business.asp

"Business visitors

A business visitor is someone who comes to Canada to engage in international business activities without directly entering the Canadian labour market. Business visitors usually stay in Canada for a few days or a few weeks but are able to stay for up to 6 months. A business visitor is a separate category with separate requirements. Business visitors do not require a work permit. For more information, see information for business visitors."

That might work as a freelancer.

And this wording is interesting:

"Business people covered by NAFTA do not need a labour market opinion (LMO) from Human Resources and Skills Development Canada (HRSDC). This means that Canadian employers do not need to have a job offer approved by HRSDC to hire an American or a Mexican business person, as set out in NAFTA."

I am not a lawyer and definitely not particularly familiar with Canadian law. Just found this page that seemed that it might have some answers to part of your question.

Frank

I thought the business visitor case might not apply because he was hoping to move for several years, but it might be worth looking into the conditions for renewal (though 5 renewals might be pushing his luck).

The wording on the NAFTA bit doesn't help as much as you might hope, though; GP doesn't match any of the long-term categories so his main sticking point is the 6-month maximum for business visitors.