unfold – pre-production site?

Dear Team
I deeply look at your demo, and unfold theme seems to meet all my requirement.
We aim at building a website for our thriathlon team (explains our goals, our history, show our partners, Team members, events, race result and race reports + blog + 2 language : French/English (using WPML pluggin I assume) … nothing really outstanding !)

We would like to develop our web site on a pre-production environment (url : http://onlinexav.fr/proto) during one month, and then move to production with another url : http://teamargon18france.fr

Should I buy 2 licences or only one licence is enough? (I hope ONE, as after move to production, we will disable the pre-production environment).

Thanks in advance.

Xavier
Team Argon 18 France