Well from what I've read on the job boards, there are plenty of jobs that need to be filled in your field and many of them do sponsor. If you check out a job forum called
indeeddotcom or
craigslist there are recruiters in the forums that are actively looking for people. The only thing is they are restricted to certain states so it really all depends on what state your gf's job is in.
Right now as you know the economy is tough so sponsorship right now is very tight. They will look above and beyond for a US citizen or green card holder first before they consider a "foreigner" like you and I. However, I know many companies are willing to accept anybody qualified under NAFTA just not to sponsor. I say this because my husband is now on a
TN as an instructor at a local college. When he said sponsor they said "NO" because of budget cuts. When he mentioned
TN visa and explained the process, they said OK and who knows, maybe in the long run they will like him and decide to sponsor him. For now he is just happy to get the experience so any visa for him right now is fine.
As for being physically in the city, that may be true. But when you come back to Canada with the job offer and letter in hand, the officer will question as to what your original intent was during your last visit. Just something to keep in mind.
Overall, you might not want to bring "sponsorship" into the equation when seeking a job right at first. If they seem reluctant to sponsor, you will tell them of the option to get a TN, then when they're comfy enough with your work ethic, you switch to an H1B.
The doable part in a long stretch will be for you to look for a job, get the job, then for the company to sponsor even though the H1B quota hasn't been met. Nobody can guarantee this will happen within a 6 month period.