I really dont know what happens after sept...
so far in my experiance they just looked at my PR papers, sometimes not even that and let me in. As far as I can tell the 183 days cannot be calculated in a reliable way, since the US INS dont stamp the passport nor do the Can Imm.
I have kept my receipts and bank statements , other letters for
SIN, health card, drivers lic, auto club , credit card to prove that I have been in canada for the time I say I have been.
take a chance, dont volenteer information, I think you should be ok.