You may easily travel outside Canada, after holding a Canadian PR. But, you must meet certain residency requirements to retain your PR status.
To meet these residency requirements, you must physically stay in Canada for at least 2 years in every 5 year period. Immigration, Refugees and Citizenship Canada (IRCC) will check the time you stay in Canada over the previous 5 years, which means you can spend 3 years outside Canada in a 5-year time. If you have a PR for less than 5 years and you want to leave Canada for a long time, in this case, you have to convince IRCC that you will surely meet your residency requirements.
If you stay outside Canada for an extended period, you can save your residency days in the following conditions:
• Traveling with a Canadian spouse or are accompanying a parent who has a child under 19 years of age
• Employed either by a Canadian employer or the Public Service of Canada on a full-time basis and are offered a job outside of Canada
• The child or spouse of a permanent resident who is staying outside Canada and is employed by a Canadian employer or the public service of Canada on a full-time basis.
While staying in Canada, an immigration officer may issue a departure order to leave Canada if he determines that you have not fulfilled your residency requirements, whereas the immigration agent will inform you in writing if you are outside Canada that you have lost your PR status because of not fulfilling your residency obligations.
If you lose your PR status, you can file an appeal within 60 days of receiving the letter from Canadian immigration authority. If you appeal politely, the officer may think on humanitarian grounds before making a final decision about your Canada Permanent Resident Visa status.
In a nutshell, if you are really interested to retain your PR status, this is extremely important to contact IRCC and let them know you will be out of Canada for some time and you will be coming back to the country without fail.