it is possible that you will get into big trouble

I landed Canada with F1 status with AP. I thought that I will be able to get back with F1, as suggested by most of the professionals I consulted. But when I came back, I was asked again and again about my 485 status and had to use my AP to get back. I don't know whether they will let me come back with F1 if I don't have AP. Actually, if that happens, it could be worse. I was told later that, if I came back with F1, my 485 will be invalid as F1 is not compatible with 485 pending. So think twice before you go and I highly suggest you bring your AP with you if you really decide to go. YOu don't want to give up your US PR for a Canadian backup, right?
Good luck.