If you spend more than 1095 days abroad during the first five years following the day you landed, you will be in breach of the PR Residency Obligation and at risk for being adjudicated to be inadmissible, resulting in loss of PR status.
In your scenario you would be cutting it so close as to be putting yourselves at significant risk. Moreover, if you actually wait to return to Canada after being abroad exactly 1094 days (say), you could not leave Canada for more than two days in the next two years without breaching the PR RO. That is, even if you stayed in Canada for a full year, upon your return, if you left Canada for more than two days your presence in Canada will be less than 730 days within the preceding five years (as of that time, which is what counts). In particular, even if you apply for and are issued a new PR card within the first year after you return, if you leave again before spending a full two years in Canada you will be in breach of the PR RO.
Some (longer) explanation for the above:
Technically, you will be in compliance with the PR RO if you return to Canada at least the day before you have been abroad 1096 days. But if you cut it close to 1095 days remember that the burden of proving compliance is on YOU, so if CIC has any reason to question, to doubt, you were actually present in Canada some of the time you declare you have been present in Canada, that can be a problem.
Thus, applying for a PR card with less than 800 days of presence within the preceding five years risks CIC having questions, which should be for obvious reasons (such a person obviously has been spending more time outside Canada than in Canada, so for any time there is less than a clear showing of presence, it is readily inferred that the PR was outside Canada, since, after all, that has been where the PR usually has been). Thus, there is a risk CIC will refer the PR to Secondary Review, with a potential for a full-blown Residency Determination which would not only result in a long delay in processing the PR card application but will require the PR to document (including evidence of activity in Canada such as employment, filing taxes in Canada, and so on) the time present in Canada, again the burden of proving presence on the PR.
Moreover, as suggested above, there is a significant pitfall lurking in your scenario. Again technically, yes, if you have been in Canada 485 days following the date of landing, and you return to Canada in time to avoid being outside Canada more than 1095 days, you will be in compliance and eligible for a new PR card. (To apply for the new card you would not have to wait, until being present 245 days, since the days remaining until the fifth anniversary of landing still count as days toward compliance . . . right up to the day of the fifth year anniversary of the day you landed . . . not the date the PR card expires but the date that is exactly five years from the day you landed.)
But in this scenario you will not have more than 730 days presence counting toward compliance with the PR Residency Obligation until you have been in Canada, after your return, for at least two years. Remember, days more than five years previous drop out of the residency calculation.
So, if for example you are abroad exactly 1095 days before returning to Canada, once you reach the fifth year anniversary, for every day you remain in Canada after that you lose a day from that initial 485 days spent in Canada. That is, if you go abroad for 1095 days, the presence that counts toward compliance will remain at 730 for a full two years following the date you return. Possession of a newly issued PR card will not allow you travel abroad without slipping into a breach of the PR RO during those two years.
Note, to be clear, zardoz has it right about credit toward presence: PR child accompanying a Canadian citizen parent gets credit toward the PR RO while abroad . . . NOT the other way around . . . that is, there is NO credit for the PR parent who is living with a Canadian citizen child abroad.
