Preferably, you don't travel at all.
It is a gift of good luck if you are able to enter Canada while not meeting the RO without getting reported.
Even if you are visa exempt or have a valid PR card, any time you travel and return while not meeting the RO, you take a risk that you will get reported.
If you are not visa exempt and your PR card is expired, you would only have the option of returning via the US land border or by applying for a travel document from a Canadian embassy.
If you don't meet the RO, the Canadian embassy will not give you a travel document, unless you have solid H&C grounds why you have not been able to meet the RO. Such as taking care of a dying relative or something like that. Possibly your own serious medical problem. Financial problems, job reasons, education reasons etc. would not be accepted. If you apply for a travel document and they refuse it, you would lose your PR.