Changing apple ID

Based on what I have read, I suggest you leave your Apple ID email address as a 3rd party email address because you have more flexibility if you need to change the email address. For example, if the Apple ID got compromised, you can change it to another address. I also have read of many people who were locked out of their accounts when they forgot their password. Since the recovery email address is the @iCloud email address, if you forget your password, you also can't access your email to get emails from Apple to recover your account. You can set a rescue email address, but for some people, this hasn't worked.

Note the restrictions in the article.

Apple ID Name Change. https://support.apple.com/en-us/HT202667

 What to do after you change your Apple ID or password - Apple Support     https://support.apple.com/en-us/HT204071 I suggest doing this before you change your Apple ID or password.

You are welcome. The Apple ID may not work on the device that is out of town until you change it to the new (renamed) ID. Logging out before changing the ID simplifies the change over.

I don't think making the old@old.ca a family member will work because once you make the change, old@old.ca is no longer an Apple ID.

Nope.

You are welcome. I hope you have a good day.