"Back to the Future: The Game" episodes 2-5 not downloading on iPad Mini

I played the first free episode of "Back to the Future: The Game" (1.6) on my iPad Mini (with iOS 9.3.5). Everything was fine and I decided to buy the bundle with episode 2-5. However, downloading the episodes (over wifi) persistently froze somewhere between 1% and 12%. After a long time, the game would then either close or give an error message about losing internet connection. I would then have to restart the download. I contacted Telltale's support, they responded quickly and with a lot of suggestions (restart the iPad, close all other apps, try another Wifi connection, keep trying, try a VPN), but neither of them made a difference.

I found this page where some people suggest using cellular data instead of wifi connection to get the episodes. That was not an option for me, as my iPad model is wifi only. However it gave me the idea to try to connect to the internet using internet sharing/tethering over Bluetooth from another device. Using Bluetooth internet sharing on my low end Lumia Windows Phone, I was able to download the episodes on the first attempt.
Note that similar Bluetooth internet sharing on an old HTC One M7 was not successful - the iPad was not able to connect to internet at all using that.

So - things to do if you suffer this issue:
- Contact Telltale support, even if you manage to solve this issue yourself using workarounds - if they do not know how many are having this issue, they wont fix it.
- Try either cellular data or Bluetooth internet sharing from another device, instead of Wifi, if you can.
- If it doesn't work over Bluetooth with your device - check if you have Internet connection at all over Bluetooth. If not, try another device, iOS is incompatible with many devices.
- Demand a refund if neither of the above helps.
- Mention this issue on App Store review etc.

Don't hesitate to leave a comment if this helped you or not!