I have heard of IO's in some cases demanding an address on the spot in which case you could give them a hotel I am sure you will have booked beforehand but you can update your address with CIC later. You could for example go to UPS and arrange an address with them where they will forward your mail to your real address. CIC will not send the PR card to a non-Canadian address.
If you tell the IO that you are only staying for 2 weeks and will not be in Canada when your PR cards are mailed, they may suggest that you do not go for PR cards on this trip but let them be mailed later when you are in Canada to stay. You could enter Canada without a PR card again either by using your passport and landing papers if you are visa exempt or by applying for a PR travel document at an embassy if you are not visa exempt. Once you are in Canada, you could contact CIC to tell them that it is ok to mail the PR cards and to which address, that is if you are back to Canada within 6 months of having landed. If you leave it for more than 6 months to come back to Canada to do this, you miss the chance of your first free mailed to your house PR card and will have to apply for a PR card just like people who are renewing. You would then have to pay $50, send new photos, wait 3 months and then pick it up at a CIC local office.