Legal Question in Immigration Law in Washington

Re: Immigration

You may be able to keep both cards for a little while, but eventually, you are going to lose the one that belongs to the country you do not RESIDE in. I emphasize "reside" because that goes to the heart of the matter. If you no longer reside in a country, you are not a permanent resident, but rather just a non-immigrant visitor like all the other nonimmigrant visitors on tourist or work visas.

When you fly or drive over the border, you will present your PR card, and the immigration or customs officer will usually ask you where you live. If you tell the truth, you will be placed into secondary inspection to determine what to do since you have a PR card and do not reside in country. Most likely, they will either keep your card and tell you to show up at a government office to determine what to do with you, but at the end of the day, you will likely lose your legal permanent residence status in the country in which you do not reside.

If you are eligible for naturalization in Canada, that may be one way to preserve your ability to come and go from Canada, but you will need to consult Canadian immigration attorneys for the answers to that question.

Sorry this is not what you want to read, but at least it gives you an idea of what you are looking at.