Forgot to mention, if your PR are expired just apply for new ones. Takes a couple months to process and 50 bucks per person. At least you will save your family trip.
We renewed our PRs without any issues while Citizenship was in process. Even after you take the oath, you won't get passports immediately. It will take a few weeks to apply and get passports. So, I would recommend to renew PRs. There might be other issues with expired PRs even if you don't travel. For example, the university did not want to accept my son as a Canadian resident with expired PR card.
Many thanks for your advice, I will renew our PRs