回复：紧急请教：我的加拿大移民身份是否依然有效？

if you do have permit, the days you hold a valid permit will be counted as the days you stay in Canada. If the number of days taht you have hold a valid permit plus the days you stay in Canada after you landed is over 730, you have good chance to come back.

No maple card? apply for a travel document.

my suggestion: check the official web site of CIC or write to Canadian Consulate in US yourself. Any answer you get here can only be reference.