Moving license to new server, transition period

I need to rebuild/replace a server which has script case installed and licensed with an enterprise license. This server has internet access. The new server does not have internet access, so I think I can perform an offline activation.

My question is, during a transition period we will need to run the old and new server concurrently. Can we do this and I need to be certain the old license won’t deactivate etc…

Will it take more than 30 days? You can always install a new version as a trial and develop that way for a bit then transfer license. I assume this is for development, not for run.

I cant be sure if it will take more than 30 days. Is the nature of this question due to terms and conditions or if we have two active at the same time and more than 30 days passes, will one stop working?