As a PRO+ user, you can use the Campercontact app offline. You can save the desired information offline via 'Account' and then click on 'Offline locations'. You will need to do this again if you have ever done so in the previous version of the app. This information has not been transferred.
Tip: To save space on your device, only download the offline maps and locations of the countries you will be travelling through and where you will ultimately be staying.