dpenabill,
so, one can infer from your post that one may ( or may not) face problems with US agents entering US from a third country with a purpose to cross
to canada with an expired PR card ( but with a renewal ecas).
It is always the case that one may or may not face problems with U.S. border officers. There are many, many variables which can influence which way it goes.
The key factor, of course, is what status the traveler has, as in what authorization to enter the U.S. the traveler has. And whether or not the traveler appears to be acting consistent with that status.
The typical problem reported is from those travelers who declare they are only transiting the U.S. but they do not have or do not present if asked, documentation showing purchased transportation to continue the trip to Canada. Many reports indicate that if and when such travelers offer a reasonable, credible explanation, such as they have arrangements to continue the trip by private auto, that usually, typically suffices. But of course many other factors and circumstances can influence how this goes. Entering the U.S. in a city far away from the Canadian border, for example, may invite suspicions about the proffered plan to continue the trip by driving to Canada.
Typically the U.S. border officers are not concerned much about the traveler's status in Canada, but more about whether the traveler is truthful when explaining his or her reason for arriving in the U.S. is to transit the U.S. to go to Canada. Obviously, if the U.S. border officer has concerns about the traveler's status to enter Canada, that will lead to huge concerns about the traveler's claim about traveling on to Canada.
But for most travelers with status to travel in the U.S., who have a flight or flights ultimately taking the traveler to a city near Canada (Seattle, Buffalo, Detroit) this tends to be overthinking things. Particularly for those who have traveled in the U.S. previously.
It is impossible to forecast precisely what questions will be asked. There is little to be gained by attempting to script one's answers in advance. Nonetheless, it can help to be prepared generally to deal with some more or less likely inquiries. For example:
Purpose of trip? Flying to Buffalo (or wherever) and from there traveling on to Canada. What is your status in Canada? I am a Canadian PR. Can you show me your status card (PR card)? [Present PRC, including expired PR card if that is what the traveler has. Or . . . answer]
I do not have one with me, but I have xxxx [and wait to see if the officer asks to see that alternative documentation . . . CoPR probably better than any thing other than a PR card (including expired PR card), but letters or eCas printout, whatever the traveling PR has, could help.]
And so on. There may be further questions to verify both the plans to travel on to Canada and having status to travel to Canada. There may be questions about where in Canada the traveler lives or works. These will ordinarily be merely questions to verify that the traveler is not going to stay in the U.S. or work in the U.S. or otherwise is not likely to do what the traveler claims he or she is doing. This can and usually will go smoothly for a traveler with regular status to travel in the U.S. But it can get more difficult, more probing, sometimes more confrontational, depending on the officer's demeanor and the officer's suspicions. Best to stay calm. Give honest and direct answers. Be patient. And ride out any stormy performance the officer might engage in.
But nonetheless, how it goes for any particular individual depends on many factors relevant to that particular individual. Travelers who are nationals in Western European countries might anticipate smoother sailing compared to those from the ME. Travelers with a more extensive history of travel in the U.S. with no indication of any breach of U.S. laws or rules are likely to have an easier time of it than those with minimal travel history in the U.S. Just the traveler's demeanor and way of answering questions can tend to help or not help.
The traveler who tells the U.S. officer he lives in or works in a city a long way from where the traveler says he or she is crossing the border, may face elevated or more skeptical scrutiny, since that might indicate the traveler is not being honest about why he or she is transiting the U.S.
And as noted, more than a few U.S. border officers can be overtly discriminatory toward some travelers. The U.S. is what it is, and these days that has been aggravated some from the top down. Most officers will not be that way. But more than a few will. Unfortunately.
