Best practice in IIS of redirect (wildcard) from one domain to another?


We are moving domains and servers. I have newdomain.com set up on new server (SSL).

I want to shut off old domain. I will get old domain pointed to new server.

Is it better in IIS to add the olddomain.com bindings on new server under the same IIS Site? Or is it better to create a new IIS site for olddomain.com and redirect it to the newdomain.com from there?

Another dimension in here is we could have links in both http and https but sites both require https. So one of the things I am worried about is redirecting http://olddomain.com/xyz/index.html and that it needs to redirect correctly to https://newdomain.com/xyz/index.html