I've spoken with a few people from the CBSA and they've said that if you are moving to Canada to wait out the rest of your PR that you would be allowed to move them across duty-free based on the fact that you INTEND to establish permanent residence for no less than 12 months. They pointed me to this memorandum - http://www.cbsa.gc.ca/publications/dm-md/d2/d2-2-1-eng.pdf
So, if you are just moving your stuff over and going back to the US to live, then yes, you would incur duties and taxes. But, if you are intending to stay in Canada to wait out the rest of the process, you would not incur any fees. That's how it was laid out to me by at least two senior officials.
Now, in terms of moving everything over, we're using a company called U-Pack. They have many different options, but the one we chose was to bring our stuff to their facilities, load it up on their truck, and then they bring it to a facility near us in Canada. We then pick up the goods from there and bring it to our home. It's a little more work on our end as we have to rent moving trucks in the US and in Canada, but it's a lot more cost effective. We're paying about $700 for the service. You also have the option of them delivering door-to-door, and depending on how much you have, the cost of course does go up. In our case, it's just a 1-bedroom apartment, so the cost was about $1500. The final option you have is the facility-to-door option where you bring your goods to their facility and they bring it to your doorstep in your Canadian home. That option was only about $100 less than door-to-door. So, if you don't mind the extra work and are looking to save some money, do the facility-to-facility option. That's if this company is in the area you're in and goes to the place in Canada you're going of course!