It is better never to lie to immigration because you don't know what they know and if they catch you lying, you could possibly be charged with fraud, lose your PR and pay a hefty fine too. This actually happened to some people, see http://news.nationalpost.com/2012/10/03/couple-fined-120000-for-immigration-fraud-following-government-crackdown/
If you get lucky, you won't get too many questions and will be able to enter and spend two years. If the immigration officer realizes that you do not meet the RO, they might still not report you. It also depends on why you were unable to meet the RO. The IO may be more sympathetic if you were stuck outside taking care of your sick mother than if you were outside Canada because you had a really good job and made a lot of money.
If they report you on entry, you would have to appeal for your PR stating your reasons. If you had H&C grounds, you have to prove them.