I am a student in the US and I am scheduled to defend my PhD in March. I recently got PR and need to land in Canada by mid-February. My US visa has expired and if I leave the US I don't know how much time it might take to be able to get a new visa (especially given that I am from a country with travel ban) and if I'll be able to get back to the US by my defense date. Is there a way to land in Canada (for example through Peace Arch Park) and return to the US without a visa? If not, would that be possible to contact IRCC explain the situation and ask them to extend my landing deadline by two months? Has anybody done this before?