是的，大家的确可以在没有枫叶卡或移民签证的情况下，混到美国，然后步行入境加拿大。这不是我说的，在移民部官网上有明确说明：
https://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=1457&top=10
Can I travel outside Canada without my PR card?
It depends on how you’re traveling.
If you’re traveling in a
private vehicle, you can use
other documents to return to Canada.
就算20年没有来过加拿大，只要没有主动放弃过PR身份就还是永久居民，就一定能从美国走进加拿大。但能入境加拿大并不代表万事大吉，更不代表不需要满足5年住2年的条件。如果加拿大CBSA觉得你没有永久居住的意愿，会在准许入境时签发限期离境令，离境后就会失去PR身份。
注意看下面官网链接的说明，PR身份会在下面几种情况下丧失：申请PRTD时被审核不符合条件、你自愿以书面形式放弃PR身份、以及被发出驱逐令时。20年没住在加拿大不属于下面情况中的任何一种。
最下面也明确说明了，即使没有满足条件，在任何官方决定做出之前，你仍然具有PR身份。
https://www.canada.ca/en/immigratio...-immigrants/pr-card/understand-pr-status.html
Losing your permanent resident status
You don’t lose your permanent resident status when your PR card expires. You can only lose your status if you go through an official process.
You can lose your permanent resident status if:
- an adjudicator determines you are no longer a permanent resident after an inquiry or PRTD appeal;
- you voluntarily renounce your permanent resident status;
- a removal order is made against you and comes into force; or
- you become a Canadian citizen.
Even if you don't meet the residency obligation, you are still a PR until an official decision is made on your status.