Thank you everyone for responding to my inquiry. I’m sorry to be late replying; been away a couple of days. I really appreciate all the advice!!
I hadn’t thought about publishing restrictions, including the US vs CA differences. That’s helpful, and makes sense. I have a large kindle library with the US account, and it’s served very me well, so I think I’ll leave well enough alone.
It sounds like I’m able to set up a second kindle and a new account in Canada, if I want to have two libraries, but just can’t merge them. Again, thanks muchly for the replies.