I second that. I know it’s a lot of work getting all your documents ready, and it is a pain to request official documents, have them mailed to you in Canada, etc. but it’s also the homestretch!! I would really recommend having everything with you, and a photocopy. This is not the time to assume you won’t be asked for something or that getting a document isn’t worth the effort. It would be such a shame to be delayed because of it.
I had a huge binder with me of everything we submitted to NVC with photocopies (including US spouse birth certificate) + everything they asked for the interview with photocopies + any back up documents that might help (bank statements, plane tickets, literally anything). They only ended up asking for a fraction of what I brought, but I knew I had done everything I could to pass the interview. The interview usually goes smoothly but it’s still nerve wracking. It does make you feel a lot more confident knowing you have everything you could possibly need with you 😊