With in5, you can enable Application Cache (Offline Viewing) with your web app to make your content viewable offline. When you export, you would go to in5 > Export HTML5 with in5... and on the Advanced tab, set Application Cache (Offline Viewing) to Cache All. Your viewer will need to be online to first download all the content before going offline.
Another option for offline viewing is to use a sales enablement platform such as Vablet, but the content would still be on a server and downloaded to the user's iPad.
Although you can transfer the content to an iPad, the problem is that it doesn't have an open file system like a Mac does. The iPad is designed to not let you open local HTML files for security reasons. If you wanted to try going that route, you would have to find a third-party app to open the content for you.