Hi Peter,
You can only access your enrollment from countries that you have added to the ‘allowed countries’ list. You can configure this at sign-up and also at any time in Control Panel. You will need to update this list before travelling, otherwise you will lose access.
Furthermore, Developer Tier is only available in Supported Countries. See the most up to date list on the sign up page. If you are travelling outside one of these countries you will not be able to access Developer Tier. At the time of writing Croatia is not on the list of Supported Countries.
Thanks,
Michael