As I understand it, you have to be a Rogers customer with an active Rogers service plan in order to even ask them for a SIM unlock code. I'm not sure what their policy is as to how soon they give customers these codes, or for what price.
But if you're like me and are not a current Rogers cell customer, I think the best option is to just purchase an unlock code online. You'll need to provide your IMEI code from the specific phone, and then there may be a few hours' wait for them to send you back the unlock code. RedFlagDeals users report paying about $15 to use
Get Nokia Unlock Codes - Fast Nokia Unlocking!, and about $9 to use
Other Phones | Quick Phone Unlock. I think that I used cellunlocker.net, because I've heard of them before and know them to be somewhat reputable.
Now that Rogers has had this device for a while, the 3rd-party unlocker sites don't seem to have an issue with finding a code for each IMEI number.
Congratulations, you've chosen a great device, especially as a Canadian. This particular phone, once unlocked, will run on almost every Canadian carrier (except weirdo Public Mobile) at their highest currently-available speeds: on Bell, Telus and Rogers you would get LTE (falling back to HSPA where necessary); on Wind, Mobilicity and Videotron, you get HSPA falling back to UMTS. In the US, you can get any of LTE or 3G on either AT&T or T-Mobile. Overseas, you can get HSPA on the 2100 MHz band - in Europe, Asia, etc. Just make sure you ask Wind to enable overseas roaming on your plan.
I'm only slightly jealous of the upcoming Lumia 1020 pureview, but it doesn't appear to include the AWS band for 3G. The Lumia 925 does, but it only offers slight improvements over the 920, and is currently not as easy to obtain and unlock. There is still a sense in which the Lumia 920 is one of Nokia's flagship phones with the very best in Nokia-exclusive apps, and once the GDR2 "Amber" firmware update drops, it should be even better.