Hi
Know that your PR card doesn't equal PR status. Even if your card expires, you are still a PR. You just need to maintain the residency requirement for when you go to renew it. If you live with your wife for another 10 years outside Canada with your expired card, you will still be a PR and will still meet the residency requirement (unless they change the rules in there sometime
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It is better to wait until you meet the residency requirement again by being with your wife than to try H&C grounds, as H&C is always risky. Keep in mind that you will need to have definitive proof that you were with her while you were living abroad. You can use a combination of days in Canada and days with your wife abroad, as long as they are in the 5 years immediately preceding your renewal app.
Once you want to apply for a renewal, you will need to travel back to Canada, as it can't be done from outside Canada. If you aren't visa-exempt, you will need to apply for a PR Travel Document.