No need for 3. You can do 1 or 2, but in my opinion, preference will be for 2 - have the card received at the NS address. Eliminates if there are any, questions that may form on why the receiving address is in ON. But really it does not matter very much.
You may land at the border (flag-pole) - there is even an official procedure from this from CIC that they can provide - give them a call at the call centre. You will be asked the address where the PR cards will be sent - in some few instances, CBSA may ask for proof in the form of any billing statements etc., if the address given is not that where you are currently residing. In my case, I presented the driver's license that had the NS address on it. I landed last year at the ON border (Niagara) but staying/PR in NS - I may add.
Have something handy with the address to where the PR cards are to be sent with you to present if needed at the border. Also, given the lead time to get the PR card (60+ days on CIC web, but reported by other posters as now much longer) - you may be well on your way to NS during that time.
Here is the response I got when I inquired about the "flag pole" procedure.
Sir, Madam,
Thank you for contacting Citizenship and Immigration Canada. I am pleased to follow up on your request:
Validating a Confirmation of Permanent Residence at a Land Border (Flag Pole Procedure)
Once you get your Confirmation of Permanent Residence (IMM 5292 or IMM 5688) from a Canadian visa office and, if necessary, your permanent resident visa in your passport, you must have these documents validated by an immigration officer at a port of entry. If you did not see an immigration officer when you arrived in Canada and are still in possession of your IMM 5292 or IMM 5688 document, then you must:
- Go to the American land border and explain to the officer that you do not want to enter the US; but that you want to return to Canada immediately to validate an immigration document (this is called the flag pole procedure).
- Once at the Canadian border, you must show the officer:
- your passport, travel or identity document (including secure visa counterfoil (IMM 1346), if applicable);and
- your Confirmation of Permanent Residence form and instructions issued by the Canadian visa office; and
- your proof of legal status in Canada, such as a valid work permit, study permit, temporary resident permit, or visitor document; or
- any immigration document in your possession (whether valid or not); and
- proof of implied status (if applicable), for example:
payment receipt;
copy of your application;
printout of online application;
proof of mailing.
To find the land border closest to you which offers immigration services, please visit the Canada Border Service Agency Web site.
/hth...