You can courier the passport from any country to Buffalo, New York. Only applicants from visa exempt countries(e.g. USA) can send photocopies of passport pages.
You can not "land" without first receiving your passport with the immigrant visa and the confirmation permanent residence document. Another option after receiving passport request is to travel to Buffalo, NY(US visa required) and get your passport stamped then "land" as you enter Canada. There are specific days and hours when this is possible, so check the Buffalo website.
I see you just did your medicals last week and it may be weeks before you get the passport request, so relax.