The major issue is to complain to/about your provider, not mess around with the workaround solutions.
That said once you have the list of packages, you can download them on your phone and seamlessly transfer them to your pc with Syncthing.
Have a look at dnf-automatic to do downloads only. I’m not sure how many retries it allows.
There is also the option of limiting your bandwidth on the PC so that it doesn’t choke.
Ultimately the ISP has to provide a working service.
Thank-you for that! Well said.