Load portal page content on device


I am looking at the options of setting up a number of wifi ap’s with landing pages containing specific data relevant to refugees arriving in the EU coming from Ukraine.
As the actual connectivity in the locations where these will be deployed isn’t always consistent I am looking at a way in which the content can be stored either on the device itself or on a server on the same network.
Has anyone done this before and if so I am interested in how and what their experience was.