I'm a U.S. citizen currently working in Canada. I have to travel back to the U.S. roughly every eight weeks for medical reasons, which means that I can't renew my passport by mail, since that involves sending my current passport in, and with the processing time, I likely wouldn't have it back before I need to make a cross-border trip. However, my passport will expire soon. I saw on the U.S. consulate's website that consulate appointments are severely limited at the moment due to COVID, and when I looked at the "book an appointment" page, it appears that all dates are greyed out as unavailable. I'm wondering what I should do. If my passport expires while I'm in Canada, will I have to leave the country immediately? Will I be allowed back into the U.S. with an expired passport? Is there a different way I should be trying to make a consulate appointment, besides the online booking system? Thanks.