Changing backend domain (Multistore OpenMage)

[m-overlund]

Is there a viable way to change the Backend domain in a Multistore OpenMage?

We have several domains in our OpenMage:

• domain 1, 2, 3, 4 ,5 etc.

Domain 1 is also backend URL, and we are closing this webshop, and want to redirect traffic to Domain 2.
The easiest way would be just to rewrite the whole domain og change backend domain to Domain 2 also.

Caveats

1. If we change backend domain, all API calls etc properly need to be changes too.
2. If we keep backend domain, it could be a mess to redirect all traffic, but not api/extension addresses etc.

What's most feasable? :-)