That's good news. Sorry for being so slow to respond. I just got a job putting up dozens of signs in Toronto and I'm juggling that with responsibilities in Gatineau, so I barely have any time to even sleep.
I think it took several days (5 days?) between the time the CoPR was printed and when it was mailed, and that was a few days after the decision was made. After that it still took time to get it in the mail, and we are just across the river from the case processing centre, but I understand that all mail now goes to Montreal to be sorted from both Ottawa and Gatineau, so nothing can take less than 2 days.
In my experience, it is very unusual to get a letter from Ottawa/Gatineau to the northern U.S. in less than 10 days. Sometimes, it does take a bit longer. Only in rare cases is it ever as short as a week, so be patient. (I know how very hard that is.)
My partner finally landed and today he got his SIN. It's a long story that I'd like to tell, but I'm too exhausted at the moment.