Offer for mirror by tetaneutral.net in France
As proposed by email, https://tetaneutral.net/ would be happy to help mirror F-droid packages. We are a non-profit ISP based in Toulouse, France, with our own AS. We already provide mirrors for Debian, LineageOS, OpenWrt, Openstreetmap, Tails.
We can create fdroid.tetaneutral.net with HTTPS, and provide up to 300 GB of storage (SSD-based). We can either pull from the f-droid master through rsync (every hour in a cron for instance), or if you prefer we can setup a push-based approach with rsync over SSH.