Yeah, I understand, but the timeline you described may require more than 60 days, what if you start a 60 days license on June 1st, then your defense is postponed to the middle of August?
Being honest, based on similar posts I would not have my hopes up on getting a 60 days license and would focus on making the implementation something that can be recrated quickly.
For the cluster use docker, there is the official documentation on how to start it using docker.
For your custom data you may snapshot it and restore in each new cluster, or just index it again every time, it may be easier to just index it every time if you start the process thinking in this way.
For the security rules you can export and impor them without any issue.
If you have any doubts about those steps you may open a different topic so people on the forum can help or guide you.
But, let's see what Elastic answers.