We all sign an intend to reside in SK and if this intention changes at the time of landing and you land elsewhere, definitely, immigration officer has the authority to yank the PR. This is know to most of the people. Reference -
http://meurrensonimmigration.com/pnp-participants-denied-entry-at-the-border/
Now, if you land in SK, but then move to other province, many quote Canada's Freedom of Movement charter and say you can move and settle anywhere.
However, legally, I understand that the inadmissibility for misrepresentation (A40) can be applied even after landing. If you look at the case Baro v. Canada (Citizenship and Immigration), 2007 FC 1299 (CanLII) (for example),
http://www.cba.org/cba/cle/pdf/imm13_paper_mccrea.pdf , you will see that misrepresentation can be applied after landing. Specifically, under the Immigration and Refugee Protection Act, S.C. 2001, c. 27.
Will misinterpretation be applied for people who make intention to reside in a province but move elsewhere? This no one knows and I have not read anywhere till now that someone lost PR because they did not reside in the province that nominated them.
In my opinion, practically, one should always make an attempt to settle in the province that nominated them. If this is not possible, say due to not finding a job but you can find a job in another province, the province needs to be informed and only after that such a move should be done. This is because as per
http://www.cba.org/cba/cle/pdf/imm13_paper_mccrea.pdf "Failure to Disclose" can also be considered as misinterpretation. I personally would make all attempts to settle in SK and if god forbid, I cannot settle, I will not move unless I discuss this with SINP - better safe than sorry.
Failure to Disclose
Innocent misrepresentations include statements that are not accurate. More problematic
are those cases where, although not asked, one fails to disclose information that which
is relevant and material.
Also, CIC is aware of the issue where people make intention to reside to get through PNP program and end up not making any effort. Currently they have not be doing anything about it but would anyone want to take chance and leave such an issue where some action might be taken on this?
http://www.cic.gc.ca/english/department/media/speeches/2012/2012-01-26.asp
I know I have not answered the question definitively but I hope it helps.