I agree that the SAFEST approach is that offered by
@scylla
"Don't submit the application to renew your PR card until you have at least 730 days in the last five years."
The rest of that is not so simple or definitive. In particular, it is NOT necessarily the case that "
If you are a few days short, that will be a problem."
It can be a problem. That is, there is a RISK that IRCC will conduct a formal Residency Obligation examination and calculation when processing the PR card application, and if AS of THAT DATE, the date of that formal RO calculation, you are still short of meeting the PR RO, issue you a Departure Order terminating your PR status in Canada. (There is a right of appeal, as discussed at length in other topics here.)
But the details can matter, and certain details are likely to matter a lot. The range in RISK can vary from just some RISK to a fairly HIGH RISK.
Quantifying the risks is very tricky, and in a forum setting like this, too speculative to be done in anyway that is likely to help much.
We can point to some key factors which will tend to push the RISKS in one direction or the other.
The biggest factor, for example, depends a lot on just precisely how many days short. In this regard, no advanced degrees in rocket science necessary to see the trajectory of risk compared to bigger shortfalls. The more the PR is short, the bigger the risks.
And for how much longer the PR will continue to be short can be a factor. Consider the PR whose days IN Canada are in the last three years or so, for example, and for whom each new day IN Canada adds another day to the count of days IN Canada (compared, for example, to the PR who was in Canada five years ago, so for each new day in Canada is also losing a day, as it falls outside the five years that count, and thus for whom for some time will have the same calculation of total days . . . until the PR reaches the date that days from five years past are no longer falling out of the calculation). If this PR is more than a "few" days short, but even two months short, it is very likely that applying today is NOT going to be a problem. By the time IRCC opens the application, assuming the PR STAYS in Canada, the PR will be in compliance or so close that the PR will be in compliance before any scheduled RO examination. And if the PR is in compliance by the date of the formal calculation, that means the previous breach of RO is cured, and there is no basis to find the PR inadmissible.
That is a fairly complex example, and in real life there are likely to be some wrinkles, some twists and turns, making it tricky to evaluate the odds. Which leads back to the important key thing that
@scylla stated, which again (since it is important enough to warrant emphasis),
the SAFE approach is to WAIT until the RO is met before making a PR card application (and BEFORE making a sponsorship application for PR for a spouse).
And even in that example, it warrants remembering that the date of an application does not necessarily correlate to how soon a new card is actually delivered. Not only will waiting longer to apply reduce, and eventually eliminate the RISKS, doing that will also reduce the RISK of non-routine processing, so that the new PR card is issued and delivered faster . . . waiting to apply can lead to getting the PR card sooner.
BUT . . . there are many other scenarios, each with its own twists and turns. For example, depending on how long the PR card has been expired, in the province of Ontario, for example, an expired PR card is accepted as proof of status for establishing OHIP eligibility.
And otherwise, depending on just how "few" days short the PR is, compared to many other factors, including just how big a difference it makes for the individual, whether they have a valid PR card or not (such as already noted, health coverage can be obtained in Ontario; if in a province where health coverage cannot be obtained, then a factor is whether the individual can get by without health insurance), the PR can make a PR card application relying on relief from the RO based on H&C considerations. That is, the PR can choose to take some RISK because the PR really needs a new PR card.
But again, calculating those RISKS is very tricky. Considering whether to go that route virtually demands the help of a qualified, experienced, reputable immigration LAWYER (not a consultant), someone who can go over every detail in confidence and who has the experience to judge these things.
NOTE: I have barely scratched the surface of relevant factors. I note, for example, that you say "
I have now moved back to Canada . . . to renew my card and work." Among the many factors which can have influence is the nature and extent to which you are established in Canada, the extent to which the circumstances tend to show you are, or are not, SETTLED PERMANENTLY in Canada. Again, this is just one aspect of things among many. But many PRs confuse what the law (such as the PR RO) ALLOWS versus what the law intends (for PR status, it intends for PRs to settle to live in Canada PERMANENTLY), and how this can influence how things go.
In any event . . . the SAFE approach is noted with emphasis. There are alternative paths with some RISKS. Figuring out how to navigate your way forward from here is a very individual case specific endeavor, for you to figure out, and you probably could use a lawyer's help . . . unless you are prepared to simply stay long enough to get into compliance, WAITING to get into compliance BEFORE applying for a new PR card, and BEFORE making a sponsorship application for PR for a spouse.